Leeds United demonstrated all of their attacking flair as they embarrassed West Brom and left Sam Allardyce still searching for his first win as Albion manager.
Marcelo Bielsa's side scored four goals in a rampant first-half display, leaving Allardyce looking glum before compounding his misery with a fifth after the break.
After a tight start, Leeds were gifted the opening goal when Albion's Romaine Sawyers bizarrely passed into his own net from 25 yards.
From that point Leeds utterly dominated. Ezgjan Alioski's crisp drive and Jack Harrison's thumping close-range finish left Albion trailing 3-0, while worryingly devoid of ideas and confidence.