diff --git a/packages/playwright-core/src/server/fetch.ts b/packages/playwright-core/src/server/fetch.ts
index 9a062229f5..52eb9d0660 100644
--- a/packages/playwright-core/src/server/fetch.ts
+++ b/packages/playwright-core/src/server/fetch.ts
@@ -313,7 +313,7 @@ export abstract class APIRequestContext extends SdkObject {
         if (response.statusCode === 401 && !options.headers!['authorization']) {
           const auth = response.headers['www-authenticate'];
           const credentials = this._defaultOptions().httpCredentials;
-          if (auth?.trim().startsWith('Basic ') && credentials) {
+          if (auth?.trim().startsWith('Basic') && credentials) {
             const { username, password } = credentials;
             const encoded = Buffer.from(`${username || ''}:${password || ''}`).toString('base64');
             options.headers!['authorization'] = `Basic ${encoded}`;
diff --git a/tests/global-fetch.spec.ts b/tests/global-fetch.spec.ts
index 1aa36e4383..8aae416919 100644
--- a/tests/global-fetch.spec.ts
+++ b/tests/global-fetch.spec.ts
@@ -115,6 +115,24 @@ it('should return error with wrong credentials', async ({ playwright, server })
   expect(response.status()).toBe(401);
 });
 
+it('should support WWW-Authenticate: Basic', async ({ playwright, server }) => {
+  let credentials;
+  server.setRoute('/empty.html', (req, res) => {
+    if (!req.headers.authorization) {
+      res.writeHead(401, { 'WWW-Authenticate': 'Basic' });
+      res.end('HTTP Error 401 Unauthorized: Access is denied');
+      return;
+    }
+    credentials = Buffer.from((req.headers.authorization).split(' ')[1] || '', 'base64').toString();
+    res.writeHead(200, { 'content-type': 'text/plain' });
+    res.end();
+  });
+  const request = await playwright.request.newContext({ httpCredentials: { username: 'user', password: 'pass' } });
+  const response = await request.get(server.EMPTY_PAGE);
+  expect(response.status()).toBe(200);
+  expect(credentials).toBe('user:pass');
+});
+
 it('should use socks proxy', async ({ playwright, server, socksPort }) => {
   const request = await playwright.request.newContext({ proxy: {
     server: `socks5://localhost:${socksPort}`,