Watkins became the fourth player to score in four consecutive matches against Brighton as he tapped the ball home from Matty Cash’s cross in the 14th minute.
It got worse for Brighton in the 26th minute when Pervis Estupinan turned Diaby’s wayward shot into his own net.
Brighton got a goal back five minutes into the second period as Ansu Fati, one of three half-time substitutes by Roberto De Zerbi, scored his first Premier League goal with his second touch of the match.
Watkins completed his second Premier League hat-trick in the 65th minute as his shot on the breakaway was deflected past Steele by Adam Webster.
Jacob Ramsey added a fifth thanks to a brilliant curling effort from the edge of the box, with Watkins adding an assist to his tally.
Douglas Luiz sent Villa above Brighton into third with the sixth goal, following up after Steele had blocked Watkins’ shot. It is also Villa's 10th win in a row at home in the competition.
Oliver George Arthur Watkins. 🎩 pic.twitter.com/3XbNnIG1cr— Aston Villa (@AVFCOfficial) September 30, 2023
What the managers said
Roberto De Zerbi: “We played a very bad game, without mental energy. The biggest responsibility for the defeat is mine. In the second half we started better but after that we conceded three goals without a reaction – I didn’t like it. You have to be ready to give your best but we can’t lose every tackle, every duel and every second ball.
“It’s very tough to play every three days, but we have to adapt. We want to compete in every competition and we have to show that we are ready to do that." See more