diff --git a/packages/playwright-test/src/runner.ts b/packages/playwright-test/src/runner.ts
index 3ea16950c9..9b78795ca1 100644
--- a/packages/playwright-test/src/runner.ts
+++ b/packages/playwright-test/src/runner.ts
@@ -273,25 +273,25 @@ export class Runner {
       preprocessRoot._addSuite(fileSuite);
     }
 
-    // 2. Filter tests to respect line/column filter.
+    // 2. Complain about duplicate titles.
+    const duplicateTitlesError = createDuplicateTitlesError(config, preprocessRoot);
+    if (duplicateTitlesError)
+      fatalErrors.push(duplicateTitlesError);
+
+    // 3. Filter tests to respect line/column filter.
     filterByFocusedLine(preprocessRoot, testFileReFilters);
 
-    // 3. Complain about only.
+    // 4. Complain about only.
     if (config.forbidOnly) {
       const onlyTestsAndSuites = preprocessRoot._getOnlyItems();
       if (onlyTestsAndSuites.length > 0)
         fatalErrors.push(createForbidOnlyError(config, onlyTestsAndSuites));
     }
 
-    // 4. Filter only
+    // 5. Filter only.
     if (!list)
       filterOnly(preprocessRoot);
 
-    // 5. Complain about clashing.
-    const duplicateTitlesError = createDuplicateTitlesError(config, preprocessRoot);
-    if (duplicateTitlesError)
-      fatalErrors.push(duplicateTitlesError);
-
     // 6. Generate projects.
     const fileSuites = new Map<string, Suite>();
     for (const fileSuite of preprocessRoot.suites)
diff --git a/tests/playwright-test/runner.spec.ts b/tests/playwright-test/runner.spec.ts
index 6503aa5d5e..becf9ff28d 100644
--- a/tests/playwright-test/runner.spec.ts
+++ b/tests/playwright-test/runner.spec.ts
@@ -170,7 +170,7 @@ test('should use the first occurring error when an unhandled exception was throw
   expect(result.exitCode).toBe(1);
   expect(result.passed).toBe(0);
   expect(result.failed).toBe(1);
-  expect(result.report.suites[0].specs[0].tests[0].results[0].error.message).toBe('first error');
+  expect(result.report.suites[0].specs[0].tests[0].results[0].error!.message).toBe('first error');
 });
 
 test('worker interrupt should report errors', async ({ runInlineTest }) => {
@@ -303,7 +303,7 @@ test('should not hang if test suites in worker are inconsistent with runner', as
   expect(result.passed).toBe(1);
   expect(result.failed).toBe(1);
   expect(result.skipped).toBe(1);
-  expect(result.report.suites[0].specs[1].tests[0].results[0].error.message).toBe('Unknown test(s) in worker:\nproject-name > a.spec.js > Test 1 - bar\nproject-name > a.spec.js > Test 2 - baz');
+  expect(result.report.suites[0].specs[1].tests[0].results[0].error!.message).toBe('Unknown test(s) in worker:\nproject-name > a.spec.js > Test 1 - bar\nproject-name > a.spec.js > Test 2 - baz');
 });
 
 test('sigint should stop global setup', async ({ runInlineTest }) => {
@@ -423,3 +423,41 @@ test('sigint should stop plugins 2', async ({ runInlineTest }) => {
   expect(output).toContain('Plugin1 teardown');
   expect(output).not.toContain('Plugin2 teardown');
 });
+
+test('should not crash with duplicate titles and .only', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'example.spec.ts': `
+      const { test } = pwt;
+      test('non unique title', () => { console.log('do not run me'); });
+      test.skip('non unique title', () => { console.log('do not run me'); });
+      test.only('non unique title', () => { console.log('do run me'); });
+    `
+  });
+  expect(result.exitCode).toBe(1);
+  expect(stripAnsi(result.output)).toContain([
+    ` duplicate test titles are not allowed.`,
+    ` - title: non unique title`,
+    `   - example.spec.ts:6`,
+    `   - example.spec.ts:7`,
+    `   - example.spec.ts:8`,
+  ].join('\n'));
+});
+
+test('should not crash with duplicate titles and line filter', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'example.spec.ts': `
+      const { test } = pwt;
+      test('non unique title', () => { console.log('do not run me'); });
+      test.skip('non unique title', () => { console.log('do not run me'); });
+      test('non unique title', () => { console.log('do run me'); });
+    `
+  }, {}, {}, { additionalArgs: ['example.spec.ts:8'] });
+  expect(result.exitCode).toBe(1);
+  expect(stripAnsi(result.output)).toContain([
+    ` duplicate test titles are not allowed.`,
+    ` - title: non unique title`,
+    `   - example.spec.ts:6`,
+    `   - example.spec.ts:7`,
+    `   - example.spec.ts:8`,
+  ].join('\n'));
+});