diff --git a/src/compiler/output-targets/dist-lazy/generate-lazy-module.ts b/src/compiler/output-targets/dist-lazy/generate-lazy-module.ts
index f9460cfea48..fd869ca4868 100644
--- a/src/compiler/output-targets/dist-lazy/generate-lazy-module.ts
+++ b/src/compiler/output-targets/dist-lazy/generate-lazy-module.ts
@@ -240,11 +240,13 @@ const writeLazyChunk = async (
     destinations.map((dst) => {
       const filePath = join(dst, rollupResult.fileName);
       let fileCode = code;
+      const writes: Promise<any>[] = [];
       if (sourceMap) {
         fileCode = code + getSourceMappingUrlForEndOfFile(rollupResult.fileName);
-        compilerCtx.fs.writeFile(filePath + '.map', JSON.stringify(sourceMap), { outputTargetType });
+        writes.push(compilerCtx.fs.writeFile(filePath + '.map', JSON.stringify(sourceMap), { outputTargetType }));
       }
-      compilerCtx.fs.writeFile(filePath, fileCode, { outputTargetType });
+      writes.push(compilerCtx.fs.writeFile(filePath, fileCode, { outputTargetType }));
+      return Promise.all(writes);
     }),
   );
 };
@@ -281,11 +283,13 @@ const writeLazyEntry = async (
     destinations.map((dst) => {
       const filePath = join(dst, rollupResult.fileName);
       let fileCode = code;
+      const writes: Promise<any>[] = [];
       if (sourceMap) {
         fileCode = code + getSourceMappingUrlForEndOfFile(rollupResult.fileName);
-        compilerCtx.fs.writeFile(filePath + '.map', JSON.stringify(sourceMap), { outputTargetType });
+        writes.push(compilerCtx.fs.writeFile(filePath + '.map', JSON.stringify(sourceMap), { outputTargetType }));
       }
-      return compilerCtx.fs.writeFile(filePath, fileCode, { outputTargetType });
+      writes.push(compilerCtx.fs.writeFile(filePath, fileCode, { outputTargetType }));
+      return Promise.all(writes);
     }),
   );
 };
diff --git a/src/compiler/output-targets/dist-lazy/lazy-bundleid-plugin.ts b/src/compiler/output-targets/dist-lazy/lazy-bundleid-plugin.ts
index 39a3bfaeaca..ddcc731270e 100644
--- a/src/compiler/output-targets/dist-lazy/lazy-bundleid-plugin.ts
+++ b/src/compiler/output-targets/dist-lazy/lazy-bundleid-plugin.ts
@@ -37,6 +37,20 @@ export const lazyBundleIdPlugin = (
     async generateBundle(_, bundle) {
       const files = Object.entries<OutputChunk>(bundle as any);
       const map = new Map<string, string>();
+      const filesToDelete: string[] = [];
+
+      // For browser builds, loader entries are skipped by writeLazyEntry
+      // So we need to delete their sourcemaps to avoid orphaned files
+      if (suffix && config.sourceMap) {
+        for (const [key, file] of files) {
+          if (file.type === 'chunk' && file.isEntry && file.name === 'loader') {
+            const mapFileName = key + '.map';
+            if (bundle[mapFileName]) {
+              filesToDelete.push(mapFileName);
+            }
+          }
+        }
+      }
 
       for (const [_key, file] of files) {
         if (!file.isEntry) continue;
@@ -44,7 +58,16 @@ export const lazyBundleIdPlugin = (
         const entryModule = buildCtx.entryModules.find((em) => em.entryKey === file.name);
         if (!entryModule) continue;
 
-        map.set(file.fileName, (await getBundleId(file.name, file.code, suffix)) + '.entry.js');
+        const newFileName = (await getBundleId(file.name, file.code, suffix)) + '.entry.js';
+        map.set(file.fileName, newFileName);
+
+        // If we're renaming the file, mark the old sourcemap for deletion
+        if (file.fileName !== newFileName && config.sourceMap) {
+          const oldMapFileName = file.fileName + '.map';
+          if (bundle[oldMapFileName]) {
+            filesToDelete.push(oldMapFileName);
+          }
+        }
       }
 
       if (!map.size) return;
@@ -52,8 +75,11 @@ export const lazyBundleIdPlugin = (
       for (const [_key, file] of files) {
         if (!file.isEntry) continue;
 
-        file.facadeModuleId = map.get(file.fileName) || file.facadeModuleId;
-        file.fileName = map.get(file.fileName) || file.fileName;
+        const newFileName = map.get(file.fileName);
+        if (!newFileName) continue;
+
+        file.facadeModuleId = newFileName;
+        file.fileName = newFileName;
 
         const magicString = new MagicString(file.code);
 
@@ -70,6 +96,11 @@ export const lazyBundleIdPlugin = (
           file.map = magicString.generateMap();
         }
       }
+
+      // Delete orphaned sourcemap files
+      for (const fileName of filesToDelete) {
+        delete bundle[fileName];
+      }
     },
   };
 };
diff --git a/src/compiler/output-targets/dist-lazy/write-lazy-entry-module.ts b/src/compiler/output-targets/dist-lazy/write-lazy-entry-module.ts
index d6a46f92b06..46864eca74c 100644
--- a/src/compiler/output-targets/dist-lazy/write-lazy-entry-module.ts
+++ b/src/compiler/output-targets/dist-lazy/write-lazy-entry-module.ts
@@ -21,10 +21,13 @@ export const writeLazyModule = async (
 
   await Promise.all(
     destinations.map((dst) => {
-      compilerCtx.fs.writeFile(join(dst, fileName), code, { outputTargetType });
+      const jsPath = join(dst, fileName);
+      const mapPath = jsPath + '.map';
+      const writes: Promise<any>[] = [compilerCtx.fs.writeFile(jsPath, code, { outputTargetType })];
       if (!!sourceMap) {
-        compilerCtx.fs.writeFile(join(dst, fileName) + '.map', JSON.stringify(sourceMap), { outputTargetType });
+        writes.push(compilerCtx.fs.writeFile(mapPath, JSON.stringify(sourceMap), { outputTargetType }));
       }
+      return Promise.all(writes);
     }),
   );