diff --git a/playwright/_impl/_playwright.py b/playwright/_impl/_playwright.py
index 17287d145..354e3d11c 100644
--- a/playwright/_impl/_playwright.py
+++ b/playwright/_impl/_playwright.py
@@ -41,7 +41,7 @@ def __init__(
         self.webkit = from_channel(initializer["webkit"])
         self.webkit._playwright = self
 
-        self.selectors = Selectors(self._loop)
+        self.selectors = Selectors(self._loop, self._dispatcher_fiber)
         selectors_owner: SelectorsOwner = from_channel(initializer["selectors"])
         self.selectors._add_channel(selectors_owner)
 
diff --git a/playwright/_impl/_selectors.py b/playwright/_impl/_selectors.py
index 961d2b2e0..03188ea5c 100644
--- a/playwright/_impl/_selectors.py
+++ b/playwright/_impl/_selectors.py
@@ -22,10 +22,11 @@
 
 
 class Selectors:
-    def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
+    def __init__(self, loop: asyncio.AbstractEventLoop, dispatcher_fiber: Any) -> None:
         self._loop = loop
         self._channels: Set[SelectorsOwner] = set()
         self._registrations: List[Dict] = []
+        self._dispatcher_fiber = dispatcher_fiber
 
     async def register(
         self,
diff --git a/tests/sync/conftest.py b/tests/sync/conftest.py
index 868729cee..d7942bf90 100644
--- a/tests/sync/conftest.py
+++ b/tests/sync/conftest.py
@@ -23,6 +23,7 @@
     BrowserType,
     Page,
     Playwright,
+    Selectors,
     sync_playwright,
 )
 
@@ -77,3 +78,8 @@ def page(context: BrowserContext) -> Generator[Page, None, None]:
     page = context.new_page()
     yield page
     page.close()
+
+
+@pytest.fixture(scope="session")
+def selectors(playwright: Playwright) -> Selectors:
+    return playwright.selectors
diff --git a/tests/sync/test_queryselector.py b/tests/sync/test_queryselector.py
new file mode 100644
index 000000000..367b90e9a
--- /dev/null
+++ b/tests/sync/test_queryselector.py
@@ -0,0 +1,360 @@
+from pathlib import Path
+
+import pytest
+
+from playwright.sync_api import Browser, Error, Page, Selectors
+
+from .utils import Utils
+
+
+def test_selectors_register_should_work(
+    selectors: Selectors, browser: Browser, browser_name: str
+) -> None:
+    tag_selector = """
+        {
+            create(root, target) {
+                return target.nodeName;
+            },
+            query(root, selector) {
+                return root.querySelector(selector);
+            },
+            queryAll(root, selector) {
+                return Array.from(root.querySelectorAll(selector));
+            }
+        }"""
+
+    selector_name = f"tag_{browser_name}"
+    selector2_name = f"tag2_{browser_name}"
+
+    # Register one engine before creating context.
+    selectors.register(selector_name, tag_selector)
+
+    context = browser.new_context()
+    # Register another engine after creating context.
+    selectors.register(selector2_name, tag_selector)
+
+    page = context.new_page()
+    page.set_content("<div><span></span></div><div></div>")
+
+    assert page.eval_on_selector(f"{selector_name}=DIV", "e => e.nodeName") == "DIV"
+    assert page.eval_on_selector(f"{selector_name}=SPAN", "e => e.nodeName") == "SPAN"
+    assert page.eval_on_selector_all(f"{selector_name}=DIV", "es => es.length") == 2
+
+    assert page.eval_on_selector(f"{selector2_name}=DIV", "e => e.nodeName") == "DIV"
+    assert page.eval_on_selector(f"{selector2_name}=SPAN", "e => e.nodeName") == "SPAN"
+    assert page.eval_on_selector_all(f"{selector2_name}=DIV", "es => es.length") == 2
+
+    # Selector names are case-sensitive.
+    with pytest.raises(Error) as exc:
+        page.query_selector("tAG=DIV")
+    assert 'Unknown engine "tAG" while parsing selector tAG=DIV' in exc.value.message
+
+    context.close()
+
+
+def test_selectors_register_should_work_with_path(
+    selectors: Selectors, page: Page, utils: Utils, assetdir: Path
+) -> None:
+    utils.register_selector_engine(
+        selectors, "foo", path=assetdir / "sectionselectorengine.js"
+    )
+    page.set_content("<section></section>")
+    assert page.eval_on_selector("foo=whatever", "e => e.nodeName") == "SECTION"
+
+
+def test_selectors_register_should_work_in_main_and_isolated_world(
+    selectors: Selectors, page: Page, utils: Utils
+) -> None:
+    dummy_selector_script = """{
+      create(root, target) { },
+      query(root, selector) {
+        return window.__answer;
+      },
+      queryAll(root, selector) {
+        return window['__answer'] ? [window['__answer'], document.body, document.documentElement] : [];
+      }
+    }"""
+
+    utils.register_selector_engine(selectors, "main", dummy_selector_script)
+    utils.register_selector_engine(
+        selectors, "isolated", dummy_selector_script, content_script=True
+    )
+    page.set_content("<div><span><section></section></span></div>")
+    page.evaluate('() => window.__answer = document.querySelector("span")')
+    # Works in main if asked.
+    assert page.eval_on_selector("main=ignored", "e => e.nodeName") == "SPAN"
+    assert page.eval_on_selector("css=div >> main=ignored", "e => e.nodeName") == "SPAN"
+    assert page.eval_on_selector_all(
+        "main=ignored", "es => window.__answer !== undefined"
+    )
+    assert (
+        page.eval_on_selector_all("main=ignored", "es => es.filter(e => e).length") == 3
+    )
+    # Works in isolated by default.
+    assert page.query_selector("isolated=ignored") is None
+    assert page.query_selector("css=div >> isolated=ignored") is None
+    # $$eval always works in main, to avoid adopting nodes one by one.
+    assert page.eval_on_selector_all(
+        "isolated=ignored", "es => window.__answer !== undefined"
+    )
+    assert (
+        page.eval_on_selector_all("isolated=ignored", "es => es.filter(e => e).length")
+        == 3
+    )
+    # At least one engine in main forces all to be in main.
+    assert (
+        page.eval_on_selector("main=ignored >> isolated=ignored", "e => e.nodeName")
+        == "SPAN"
+    )
+    assert (
+        page.eval_on_selector("isolated=ignored >> main=ignored", "e => e.nodeName")
+        == "SPAN"
+    )
+    # Can be chained to css.
+    assert (
+        page.eval_on_selector("main=ignored >> css=section", "e => e.nodeName")
+        == "SECTION"
+    )
+
+
+def test_selectors_register_should_handle_errors(
+    selectors: Selectors, page: Page, utils: Utils
+) -> None:
+    with pytest.raises(Error) as exc:
+        page.query_selector("neverregister=ignored")
+    assert (
+        'Unknown engine "neverregister" while parsing selector neverregister=ignored'
+        in exc.value.message
+    )
+
+    dummy_selector_engine_script = """{
+      create(root, target) {
+        return target.nodeName;
+      },
+      query(root, selector) {
+        return root.querySelector('dummy');
+      },
+      queryAll(root, selector) {
+        return Array.from(root.query_selector_all('dummy'));
+      }
+    }"""
+
+    with pytest.raises(Error) as exc:
+        selectors.register("$", dummy_selector_engine_script)
+    assert (
+        exc.value.message
+        == "Selector engine name may only contain [a-zA-Z0-9_] characters"
+    )
+
+    # Selector names are case-sensitive.
+    utils.register_selector_engine(selectors, "dummy", dummy_selector_engine_script)
+    utils.register_selector_engine(selectors, "duMMy", dummy_selector_engine_script)
+
+    with pytest.raises(Error) as exc:
+        selectors.register("dummy", dummy_selector_engine_script)
+    assert exc.value.message == '"dummy" selector engine has been already registered'
+
+    with pytest.raises(Error) as exc:
+        selectors.register("css", dummy_selector_engine_script)
+    assert exc.value.message == '"css" is a predefined selector engine'
+
+
+def test_should_work_with_layout_selectors(page: Page) -> None:
+    #        +--+  +--+
+    #        | 1|  | 2|
+    #        +--+  ++-++
+    #        | 3|   | 4|
+    #   +-------+  ++-++
+    #   |   0   |  | 5|
+    #   | +--+  +--+--+
+    #   | | 6|  | 7|
+    #   | +--+  +--+
+    #   |       |
+    #   O-------+
+    #           +--+
+    #           | 8|
+    #           +--++--+
+    #               | 9|
+    #               +--+
+
+    boxes = [
+        # x, y, width, height
+        [0, 0, 150, 150],
+        [100, 200, 50, 50],
+        [200, 200, 50, 50],
+        [100, 150, 50, 50],
+        [201, 150, 50, 50],
+        [200, 100, 50, 50],
+        [50, 50, 50, 50],
+        [150, 50, 50, 50],
+        [150, -51, 50, 50],
+        [201, -101, 50, 50],
+    ]
+    page.set_content(
+        '<container style="width: 500px; height: 500px; position: relative;"></container>'
+    )
+    page.eval_on_selector(
+        "container",
+        """(container, boxes) => {
+    for (let i = 0; i < boxes.length; i++) {
+      const div = document.createElement('div');
+      div.style.position = 'absolute';
+      div.style.overflow = 'hidden';
+      div.style.boxSizing = 'border-box';
+      div.style.border = '1px solid black';
+      div.id = 'id' + i;
+      div.textContent = 'id' + i;
+      const box = boxes[i];
+      div.style.left = box[0] + 'px';
+      // Note that top is a flipped y coordinate.
+      div.style.top = (250 - box[1] - box[3]) + 'px';
+      div.style.width = box[2] + 'px';
+      div.style.height = box[3] + 'px';
+      container.appendChild(div);
+      const span = document.createElement('span');
+      span.textContent = '' + i;
+      div.appendChild(span);
+    }
+  }""",
+        boxes,
+    )
+
+    assert page.eval_on_selector("div:right-of(#id6)", "e => e.id") == "id7"
+    assert page.eval_on_selector("div:right-of(#id1)", "e => e.id") == "id2"
+    assert page.eval_on_selector("div:right-of(#id3)", "e => e.id") == "id4"
+    assert page.query_selector("div:right-of(#id4)") is None
+    assert page.eval_on_selector("div:right-of(#id0)", "e => e.id") == "id7"
+    assert page.eval_on_selector("div:right-of(#id8)", "e => e.id") == "id9"
+    assert (
+        page.eval_on_selector_all(
+            "div:right-of(#id3)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id4,id2,id5,id7,id8,id9"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:right-of(#id3, 50)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id2,id5,id7,id8"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:right-of(#id3, 49)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id7,id8"
+    )
+
+    assert page.eval_on_selector("div:left-of(#id2)", "e => e.id") == "id1"
+    assert page.query_selector("div:left-of(#id0)") is None
+    assert page.eval_on_selector("div:left-of(#id5)", "e => e.id") == "id0"
+    assert page.eval_on_selector("div:left-of(#id9)", "e => e.id") == "id8"
+    assert page.eval_on_selector("div:left-of(#id4)", "e => e.id") == "id3"
+    assert (
+        page.eval_on_selector_all(
+            "div:left-of(#id5)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0,id7,id3,id1,id6,id8"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:left-of(#id5, 3)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id7,id8"
+    )
+
+    assert page.eval_on_selector("div:above(#id0)", "e => e.id") == "id3"
+    assert page.eval_on_selector("div:above(#id5)", "e => e.id") == "id4"
+    assert page.eval_on_selector("div:above(#id7)", "e => e.id") == "id5"
+    assert page.eval_on_selector("div:above(#id8)", "e => e.id") == "id0"
+    assert page.eval_on_selector("div:above(#id9)", "e => e.id") == "id8"
+    assert page.query_selector("div:above(#id2)") is None
+    assert (
+        page.eval_on_selector_all(
+            "div:above(#id5)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id4,id2,id3,id1"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:above(#id5, 20)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id4,id3"
+    )
+
+    assert page.eval_on_selector("div:below(#id4)", "e => e.id") == "id5"
+    assert page.eval_on_selector("div:below(#id3)", "e => e.id") == "id0"
+    assert page.eval_on_selector("div:below(#id2)", "e => e.id") == "id4"
+    assert page.eval_on_selector("div:below(#id6)", "e => e.id") == "id8"
+    assert page.eval_on_selector("div:below(#id7)", "e => e.id") == "id8"
+    assert page.eval_on_selector("div:below(#id8)", "e => e.id") == "id9"
+    assert page.query_selector("div:below(#id9)") is None
+    assert (
+        page.eval_on_selector_all(
+            "div:below(#id3)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0,id5,id6,id7,id8,id9"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:below(#id3, 105)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0,id5,id6,id7"
+    )
+
+    assert page.eval_on_selector("div:near(#id0)", "e => e.id") == "id3"
+    assert (
+        page.eval_on_selector_all(
+            "div:near(#id7)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0,id5,id3,id6"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:near(#id0)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id3,id6,id7,id8,id1,id5"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:near(#id6)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0,id3,id7"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:near(#id6, 10)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id0"
+    )
+    assert (
+        page.eval_on_selector_all(
+            "div:near(#id0, 100)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id3,id6,id7,id8,id1,id5,id4,id2"
+    )
+
+    assert (
+        page.eval_on_selector_all(
+            "div:below(#id5):above(#id8)", "els => els.map(e => e.id).join(',')"
+        )
+        == "id7,id6"
+    )
+    assert page.eval_on_selector("div:below(#id5):above(#id8)", "e => e.id") == "id7"
+
+    assert (
+        page.eval_on_selector_all(
+            "div:right-of(#id0) + div:above(#id8)",
+            "els => els.map(e => e.id).join(',')",
+        )
+        == "id5,id6,id3"
+    )
+
+    with pytest.raises(Error) as exc_info:
+        page.query_selector(":near(50)")
+    assert (
+        '"near" engine expects a selector list and optional maximum distance in pixels'
+        in exc_info.value.message
+    )
+    with pytest.raises(Error) as exc_info:
+        page.query_selector('left-of="div"')
+    assert '"left-of" selector cannot be first' in exc_info.value.message