Match ends, West Bromwich Albion 4, Leeds United 1.
West Bromwich Albion scored four second-half goals to thrash Leeds and stop them returning to the top of the Championship.
After having the better of the first half, Hal Robson-Kanu drilled low into the far corner to give the hosts a deserved lead.
Matt Phillips beat Bailey Peacock-Farrell from outside the area to double the home side's advantage and it was 3-0 when Harvey Barnes guided home when put through on goal.
Substitute Dwight Gayle backheeled in the Baggies' fourth to mark his return from injury, with Pablo Hernandez's looping header in injury time no more than a consolation for Leeds.
A first win in five for Darren Moore's side moves them up to fifth, while Leeds are third and three points behind new leaders Norwich.
Leeds had 72% of possession but managed only three shots on target, with Mateusz Klich seeing a first-half effort beaten away by Sam Johnstone.
West Brom's opener came just moments after Kemar Roofe had a penalty appeal rejected after going down under Craig Dawson's challenge.
Peacock-Farrell got a touch to Phillips' long-range effort but failed to push it clear and Leeds then folded, with Gayle's cheeky finish coming after the excellent Jay Rodriguez's shot was saved into his path.
Hernandez's stoppage-time goal denied the victors only a second league clean sheet of the season, but the Baggies have scored four or more goals in five matches in 2018-19.
West Brom head coach Darren Moore told BBC WM:
"It was a worthy three points. Everyone played their part and did very well.
"From the first minute we set about it and wanted to win the game.
"When the opportunities do come, we know we've got players in those areas of the pitch that can score goals."
Leeds head coach Marcelo Bielsa:
"I feel responsible for this loss. We knew the features of the opponent was that they needed spaces to attack.
In order to prevent the opponent from counter attacking we had not to lose the ball when we played out.
"We worked on this to prevent this from happening. If the opposite of what I designed happened I am responsible for it. What I could say is the score was a little bit too much."
- 3GibbsSubstituted forMearsat 88'minutes
- 8LivermoreBooked at 55mins
- 10PhillipsSubstituted forHarperat 90+2'minutes
- 4Robson-KanuBooked at 64minsSubstituted forGayleat 80'minutes
- 3DouglasSubstituted forHarrisonat 73'minutes
- 43KlichSubstituted forSáizat 78'minutes
- 7RoofeSubstituted forRobertsat 66'minutes
- Lee Mason
- Shots on Target
Second Half ends, West Bromwich Albion 4, Leeds United 1.
Substitution, West Bromwich Albion. Rekeem Harper replaces Matt Phillips.
Goal! West Bromwich Albion 4, Leeds United 1. Pablo Hernández (Leeds United) header from the centre of the box to the bottom right corner. Assisted by Samuel Sáiz.
Attempt blocked. Harvey Barnes (West Bromwich Albion) right footed shot from outside the box is blocked.
Foul by Ezgjan Alioski (Leeds United).
Dwight Gayle (West Bromwich Albion) wins a free kick on the right wing.
Substitution, West Bromwich Albion. Tyrone Mears replaces Kieran Gibbs.
Offside, Leeds United. Adam Forshaw tries a through ball, but Jack Harrison is caught offside.
Goal! West Bromwich Albion 4, Leeds United 0. Dwight Gayle (West Bromwich Albion) right footed shot from the centre of the box to the bottom right corner.
Attempt blocked. Jay Rodriguez (West Bromwich Albion) right footed shot from the left side of the box is blocked.
Goal! West Bromwich Albion 3, Leeds United 0. Harvey Barnes (West Bromwich Albion) right footed shot from the centre of the box to the bottom right corner. Assisted by Tosin Adarabioyo.
Attempt missed. Jack Harrison (Leeds United) left footed shot from the left side of the box is close, but misses to the left.
Samuel Sáiz (Leeds United) wins a free kick in the attacking half.
Foul by Ahmed Hegazi (West Bromwich Albion).
Substitution, West Bromwich Albion. Dwight Gayle replaces Hal Robson-Kanu.
Attempt missed. Ezgjan Alioski (Leeds United) left footed shot from the left side of the box is close, but misses to the left. Assisted by Pablo Hernández.
Attempt blocked. Tyler Roberts (Leeds United) right footed shot from the right side of the box is blocked. Assisted by Stuart Dallas.
Kalvin Phillips (Leeds United) wins a free kick on the right wing.
Foul by Jay Rodriguez (West Bromwich Albion).