Albion produced another outstanding performance as they moved above Liverpool and up to seventh in the Premier League table after three second-half goals sent the Amex into raptures.
Solly March gave Albion a richly deserved lead 70 seconds after the break and added his second six minutes later with a superb finish into the far corner for his fourth Premier League goal of the season, which have come in three of the last four matches.
Danny Welbeck put the icing on the cake with a brilliant third ten minutes from time as Albion comprehensively outplayed a Liverpool team who had won on ten of their last 11 visits to Sussex. It was Albion's first home win against them for 61 years.
The only surprise was that Albion’s winning margin wasn’t more handsome. March and Kaoru Mitoma both went close during a dominant first-half performance when VAR for a marginal offside against man of the match March meant Albion were denied a penalty.
That incident, though, will be just a footnote on a memorable Amex afternoon. Even Jurgen Klopp acknowledged that his side had been outclassed when he applauded as he approached Roberto De Zerbi at the final whistle before wrapping the Italian in a warm embrace.
De Zerbi named the same starting line-up that had beaten Everton 4-1 on our last Premier League meeting while a strong bench included Adam Webster and Welbeck.
World Cup winner Alexis Mac Allister got a fantastic reception from the crowd when he walked out to a guard of honour a few minutes before kick-off and the feel-good factor around the stadium was evident as Albion tore into the visitors, with Kaoru Mitoma and March exploiting the space behind Liverpool's defence.
March thought he’d found the bottom corner with a curling effort on eight minutes but Trent Alexander-Arnold stuck his right leg out to divert the ball out for a corner, which Mac Allister met well but directed his header at keeper Alisson.
Adam Lallana then led a break down the right which left Liverpool exposed at the back, but his pass to the unmarked Evan Ferguson was slightly behind the striker and eventually the visitors cleared.
Mitoma was next to threaten and when Alexander-Arnold brought him down he earned a yellow card. Teammate Joel Matip followed him for another late challenge on Mitoma and Lewis Dunk joined them in the book when he fouled Cody Gakpo on halfway.
Albion had their first scare in the 28th minute but Rob Sanchez managed to stretch his hand onto the ball to divert it out of Mo Salah’s path as Liverpool appealed for a foul. Albion broke and a great ball by Lallana down the left put Mitoma away. He cut in but steered his shot across Alisson and wide of the far post.
Henderson became the fourth player to be cautioned in the opening half-hour for a challenge from behind on Moises Caicedo before Mitoma left Alexander-Arnold in his wake again but this time Matip got across to make a good challenge. Another Mitoma cross only just eluded Ferguson and Pascal Gross.
Albion thought they’d earned a penalty in the 42th minute when Lallana’s pass found March, who got goal side of Ibrahima Konate, rounded Alisson and was brought down by the keeper. But March was narrowly offside and Liverpool breathed a sigh of relief. Ferguson tested Alisson in stoppage time and all that had been missing from our first-half performance was a goal or two.
But it came… 70 seconds into the second half. Matip’s pass was intercepted by Lallana who fed Mitoma. He broke into the box and passed across the face of goal to give March a simple finish. And this time there was no question of offside and it was no more than Albion deserved.
It got even better. Caicedo started the move when he found Ferguson. The striker’s pass was perfectly weighted and March was in. There was still work to do, but Solly did it in style as he smashed a left-foot shot across Alisson and inside far post. A sensational finish.
Lallana dragged a right-foot shot wide from the edge of the box after good hold-up play by Ferguson, then Mitoma cut inside but shot straight at Alisson as Albion continued to dominate.
Ferguson departed to a standing ovation when he was replaced by Welbeck and for a while Liverpool, who made four changes at the same time, perked up and Harvey Elliott should have done better with a chance 15 yards out which he snatched at and fired wide. Sanchez had not been called upon much in the second half but he made himself big to superbly block Gakpo’s close-range effort during Liverpool’s best spell.
But Albion put the result beyond doubt with nine minutes to go. Gross’s quick throw found March who played in Welbeck on the right. He lifted the ball over Joe Gomez and as it dropped smashed a volley inside the right-hand post.
With the game won, De Zerbi could take off his World Cup winner, who departed to his second standing ovation of the day, but Albion continued to hunt for more goals and Welbeck ended another great move with a shot which Alisson got right behind.
The Italian even had the luxury of substituting skipper Dunk in stoppage time. As he made his way round the pitch the home crowd stood as one to acknowledge Dunk and a performance that will live long in the memory of Albion supporters.
Albion: Sanchez, Dunk (Webster 90), Colwill, Estupinan, March, Gross, Caicedo, Mitoma (Lamptey 90), Mac Allister (Sarmiento 83), Lallana (Veltman 65), Ferguson (Welbeck 65).
Subs: Steele, Undav, Gilmour, van Hecke.
Referee: Darren England.
Attendance: 31,645