diff --git a/packages/angular/build/src/builders/application/options.ts b/packages/angular/build/src/builders/application/options.ts
index dcac17d97d1e..39e75ef7ca4d 100644
--- a/packages/angular/build/src/builders/application/options.ts
+++ b/packages/angular/build/src/builders/application/options.ts
@@ -64,8 +64,10 @@ interface InternalOptions {
    * If given a relative path, it is resolved relative to the current workspace and will generate an output at the same relative location
    * in the output directory. If given an absolute path, the output will be generated in the root of the output directory with the same base
    * name.
+   *
+   * If provided a Map, the key is the name of the output bundle and the value is the entry point file.
    */
-  entryPoints?: Set<string>;
+  entryPoints?: Set<string> | Map<string, string>;
 
   /** File extension to use for the generated output files. */
   outExtension?: 'js' | 'mjs';
@@ -519,7 +521,7 @@ async function getTailwindConfig(
 function normalizeEntryPoints(
   workspaceRoot: string,
   browser: string | undefined,
-  entryPoints: Set<string> = new Set(),
+  entryPoints: Set<string> | Map<string, string> = new Set(),
 ): Record<string, string> {
   if (browser === '') {
     throw new Error('`browser` option cannot be an empty string.');
@@ -538,6 +540,16 @@ function normalizeEntryPoints(
   if (browser) {
     // Use `browser` alone.
     return { 'main': path.join(workspaceRoot, browser) };
+  } else if (entryPoints instanceof Map) {
+    return Object.fromEntries(
+      Array.from(entryPoints.entries(), ([name, entryPoint]) => {
+        // Get the full file path to a relative entry point input. Leave bare specifiers alone so they are resolved as modules.
+        const isRelativePath = entryPoint.startsWith('.');
+        const entryPointPath = isRelativePath ? path.join(workspaceRoot, entryPoint) : entryPoint;
+
+        return [name, entryPointPath];
+      }),
+    );
   } else {
     // Use `entryPoints` alone.
     const entryPointPaths: Record<string, string> = {};
diff --git a/packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts b/packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts
index 187ca8f5468e..dce39e699eaf 100644
--- a/packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts
+++ b/packages/angular_devkit/build_angular/src/builders/karma/application_builder.ts
@@ -260,7 +260,7 @@ async function collectEntrypoints(
   options: KarmaBuilderOptions,
   context: BuilderContext,
   projectSourceRoot: string,
-): Promise<Set<string>> {
+): Promise<Map<string, string>> {
   // Glob for files to test.
   const testFiles = await findTests(
     options.include ?? [],
@@ -269,7 +269,28 @@ async function collectEntrypoints(
     projectSourceRoot,
   );
 
-  return new Set(testFiles);
+  const seen = new Set<string>();
+
+  return new Map(
+    Array.from(testFiles, (testFile) => {
+      const relativePath = path
+        .relative(
+          testFile.startsWith(projectSourceRoot) ? projectSourceRoot : context.workspaceRoot,
+          testFile,
+        )
+        .replace(/^[./]+/, '_')
+        .replace(/\//g, '-');
+      let uniqueName = `spec-${path.basename(relativePath, path.extname(relativePath))}`;
+      let suffix = 2;
+      while (seen.has(uniqueName)) {
+        uniqueName = `${relativePath}-${suffix}`;
+        ++suffix;
+      }
+      seen.add(uniqueName);
+
+      return [uniqueName, testFile];
+    }),
+  );
 }
 
 async function initializeApplication(
@@ -298,12 +319,11 @@ async function initializeApplication(
     fs.rm(outputPath, { recursive: true, force: true }),
   ]);
 
-  let mainName = 'init_test_bed';
+  const mainName = 'test_main';
   if (options.main) {
-    entryPoints.add(options.main);
-    mainName = path.basename(options.main, path.extname(options.main));
+    entryPoints.set(mainName, options.main);
   } else {
-    entryPoints.add('@angular-devkit/build-angular/src/builders/karma/init_test_bed.js');
+    entryPoints.set(mainName, '@angular-devkit/build-angular/src/builders/karma/init_test_bed.js');
   }
 
   const instrumentForCoverage = options.codeCoverage
@@ -358,6 +378,8 @@ async function initializeApplication(
     { pattern: `${outputPath}/${mainName}.js`, type: 'module', watched: false },
     // Serve all source maps.
     { pattern: `${outputPath}/*.map`, included: false, watched: false },
+    // These are the test entrypoints.
+    { pattern: `${outputPath}/spec-*.js`, type: 'module', watched: false },
   );
 
   if (hasChunkOrWorkerFiles(buildOutput.files)) {
@@ -371,10 +393,6 @@ async function initializeApplication(
       },
     );
   }
-  karmaOptions.files.push(
-    // Serve remaining JS on page load, these are the test entrypoints.
-    { pattern: `${outputPath}/*.js`, type: 'module', watched: false },
-  );
 
   if (options.styles?.length) {
     // Serve CSS outputs on page load, these are the global styles.
diff --git a/packages/angular_devkit/build_angular/src/builders/karma/tests/behavior/specs_spec.ts b/packages/angular_devkit/build_angular/src/builders/karma/tests/behavior/specs_spec.ts
new file mode 100644
index 000000000000..773f113bec83
--- /dev/null
+++ b/packages/angular_devkit/build_angular/src/builders/karma/tests/behavior/specs_spec.ts
@@ -0,0 +1,44 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import { execute } from '../../index';
+import { BASE_OPTIONS, KARMA_BUILDER_INFO, describeKarmaBuilder } from '../setup';
+
+describeKarmaBuilder(execute, KARMA_BUILDER_INFO, (harness, setupTarget, isApp) => {
+  describe('Behavior: "Specs"', () => {
+    beforeEach(async () => {
+      await setupTarget(harness);
+    });
+
+    it('supports multiple spec files with same basename', async () => {
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+      });
+
+      const collidingBasename = 'collision.spec.ts';
+
+      // src/app/app.component.spec.ts conflicts with this one:
+      await harness.writeFiles({
+        [`src/app/a/${collidingBasename}`]: `/** Success! */`,
+        [`src/app/b/${collidingBasename}`]: `/** Success! */`,
+      });
+
+      const { result, logs } = await harness.executeOnce();
+
+      expect(result?.success).toBeTrue();
+
+      if (isApp) {
+        const bundleLog = logs.find((log) =>
+          log.message.includes('Application bundle generation complete.'),
+        );
+        expect(bundleLog?.message).toContain('spec-app-a-collision.spec.js');
+        expect(bundleLog?.message).toContain('spec-app-b-collision.spec.js');
+      }
+    });
+  });
+});