Albion suffered only their second league defeat of the season with the damage done in 12 first-half minutes when Aston Villa struck three times.
At a ground which has seldom been Albion’s happy place, they were rocked by Ollie Watkins’ hat-trick, Pervis Estupinan's own goal and late strikes from Jacob Ramsey and Douglas Luiz as Villa made it ten successive home wins in the Premier League.
Behind 3-0 at the break, Albion reacted positively and substitute Ansu Fati got his first goal for the club, but Watkins’ third – he now has six goals in six games against Albion – punctured hopes of a comeback.
Fati will remember his first Premier League goal and it was also a red-letter day despite the result for 18-year-old Jack Hinshelwood, who could be pleased with his tidy midfield performance on his full Premier League debut.
Albion actually started quite well and Estupinan forced the first save after six minutes when he burst onto Billy Gilmour’s chip but Emi Martinez blocked his effort.
Then it all unravelled as Albion were rocked by three goals in 12 minutes.
They went behind on 14 minutes. John McGinn’s clever pass found Matty Cash overlapping on the right and just onside and his inviting ball across the face of goal gave Watkins an easy finish a couple of yards out and a goal in his fourth successive game against the Seagulls.
Watkins curled a right-footer a couple of yards wide of the far post before doubling Villa’s lead. Joel Veltman – on his 100th Premier League appearance – conceded possession to Moussa Diaby and he slid Watkins in on the left. The striker cut inside and drove a low right-footer inside Jason Steele’s near post.
Steele saved Diaby’s angled effort with an outstretched leg, but Villa had their third in 26 minutes. The keeper saved Diaby’s first effort he had no chance when the follow-up took a massive deflection off Estupinan. VAR checked on a foul on Solly March in the build-up, but the goal stood.
March should have done better with a free header he directed over from close range but Steele denied Villa a fourth before the break when he blocked Diaby’s drive.
Roberto De Zerbi reacted by bringing on Fati, Joao Pedro and birthday boy Tariq Lamptey for the second half and within five minutes of the restart it was 3-1. Mitoma found Pedro on the left and after his first cross was blocked his second found Fati who swept it home.
The momentum was with Albion and when Gilmour’s free-kick dropped to Fati eight yards out Boubacar Kamara had to make a crucial block. Another Albion goal would have made it interesting but when it did come it was Watkins celebrating his hat-trick. McGinn’s lofted pass found him in that familiar position cutting in from the left and his shot beat Steele with the aid of a deflection off Adam Webster.
Martinez tipped Simon Adingra’s 20-yarder over the bar but it was Villa who finished with a flourish. Substitute Jacob Ramsey found the far corner with a shot from the left-hand corner of the box and Douglas Luiz added a sixth with virtually the last kick as Albion conceded six in a game for the first time since 2012.
Albion: Steele, Veltman, Webster, Dunk, Estupinan (Lamptey 45), March (Adingra 60), Hinshelwood (Baleba 86), Gilmour, Mitoma, Welbeck (Pedro 45), Ferguson (Fati 45).
Subs not used: Verbruggen, Igor Julio, Dahoud, van Hecke.
Referee: Andy Madley
Attendance: 40,636 (2981 Albion)