Marcelo Bielsa's Whites were handed an early advantage via a comical Romaine Sawyers own goal, after which Gjanni Alioski, Jack Harrison, Rodrigo and Raphinha all bagged a goal apiece.
Graham Smyth, the YEP's chief football writer, hands out the scores.
1. Illan Meslier
8 - Redeemed himself for one poor pass with a fine save, his only save. Good in the air, distributed it well. A comfortable night. Photo by TIM KEETON/POOL/AFP via Getty Images.
2. Stuart Dallas
9 - Energy, skill, defensive solidity, was only lacking a final ball at times when he got into great positions. Terrific run for Raphinha's goal. Photo by David Rogers/Getty Images.
3. Luke Ayling
9 - Put under little pressure but he was so good on the ball, driving Leeds forward and finding space. Led, vocally, defended well when he had to. Photo by Tim Keeton - Pool/Getty Images.
4. Pascal Struijk
8 - Kept things simple but showed one or two nice passes. Like Ayling, defended well when he had to. Photo by Shaun Botterill/Getty Images.
5. Gjanni Alioski
8 - Scored a beautiful goal, got forward well, won plenty of aerial balls. West Brom did get a little joy on that flank in the first half and his composure left him briefly once or twice. Photo by Shaun Botterill/Getty Images.
6. Kalvin Phillips
9 - On cruise control. One of those games where he looked so comfortable. Pulled the strings from deep alongside the centre-halfs. Got forward well too. Photo by Rui Vieira - Pool/Getty Images.