Ollie Watkins netted a hat-trick as Albion suffered their third loss in four games in all competitions.
Looking to bounce back from the 1-0 Carabao Cup defeat at Chelsea, Roberto De Zerbi made nine changes.
However, they never really got going and found themselves a goal down after just 14 minutes when Watkins scored from Matty Cash’s cut-back.
The striker scored again seven minutes later, with a fine solo effort, after the Seagulls gave the ball away cheaply in midfield. However, Jason Steele appeared to have his vision impeded by Nicolo Zaniolo, who was standing directly in front of him in an offside position. VAR checked but ruled in favour of Villa.
Things went from bad to worse when a hapless Pervis Estupinan turned the ball into his own net after Moussa Diaby's mis-hit was going wide. There was controversy again as Solly March looked like he was fouled in the build-up.
There were shades of Everton's win at the Amex last season as Villa looked like scoring every time they went forward against an all at sea Albion side, lacking protection in front of the defence.
De Zerbi made three half-time changes, with Ansu Fati and Joao Pedro replacing the ineffective Evan Ferguson and Danny Welbeck. Estupinan also made way for Tariq Lamptey.
The substitutes made an immediate impact with Pedro battling hard to keep the ball alive before Fati tapped in from close range on the 50th minute. The goal was given after a lengthy VAR check for offside.
Suddenly, Albion looked more lively in the forward areas but there efforts to find two more goals left them even more open at the back. Watkins took full advantage by sealing his hat-trick to put the result beyond doubt.
Tensions threatened to boil over as Fati lashed out after a tussle with Ezri Konsa but he fortunately escaped with a yellow card.
Jacob Ramsey added a fifth for Villa with a delightful finish off the post to send Albion fans heading for the exit door.
Douglas Luiz added the cherry on top of the cake with a sixth goal in injury-time after Steele had saved well from Watkins.
Here’s how we rated Brighton’s players on a difficult afternoon in Birmingham.
1. Aston Villa 6-1 Brighton
Brighton’s recent dip in form continued with a 6-1 thrashing at the hands of Unai Emery’s Aston Villa (Photo by Nathan Stirk/Getty Images) Photo: Nathan Stirk/Getty Images
2. Jason Steele - 3
Didn’t look assured of himself in goal this afternoon. Made a couple of decent saves but had no chance with Watkins’ first goal. Steele will be unhappy to have been beaten at his near post for the second goal. Did his best to stop third goal from going in but had no chance after deflection off his own defender. No chance of stopping Watkins' hat trick strike or Ramsey’s curling effort. Denied Watkins’ fourth but conceded rebound anyway. Photo: James Gill/Getty Images
3. Joel Veltman - 3
Gave the ball away cheaply before the second goal. Good header across goal to March, who should have done better. made some important tackles and blocks but ultimately proved worthless. Gave Ramsey far too much time to find a finish. Photo: James Gill/Getty Images
4. Adam Webster - 3
Struggled to keep up with the pace of the game and was no match for the quick and powerful Ollie Watkins. Photo: James Gill/Getty Images