Manchester United matched their own record for the biggest home win in Premier League history as Southampton suffered the unprecedented ignominy of 9-0 defeats in consecutive seasons.
Ralph Hasenhuttl's men saw their outing at Old Trafford unravel from the moment Alexandre Jankewitz was shown a second-minute red card for an ugly lunge on Scott McTominay.
Aaron Wan-Bissaka began the rout and efforts from Marcus Rashford and Edinson Cavani either side of a Jan Bednarek own goal made it 4-0 at half-time.
Anthony Martial and McTominay made it 6-0 inside the final 20 minutes before a Bruno Fernandes penalty, Martial's second and a closing goal from Daniel James left Southampton – who also saw Bednarek sent off – in an unsightly heap.
From nine goals to nine men, Arsenal had David Luiz and Bernd Leno dismissed as they lost 2-1 at Wolves.
That scoreline was repeated in victories for Sheffield United and Crystal Palace that could have repercussions at the bottom of the table.
Manchester United 9-0 Southampton: Record-equalling joy and despair at Old Trafford
James' goal deep into stoppage time meant United won 9-0 for the first time since thrashing Ipswich Town in March 1995. It is only the third instance of this scoreline in the Premier League, following Southampton's thrashing on home turf against Leicester City in October 2019.
This fixture is not always anything like as kind to United. In fact, they have won home and away against Saints for the first time since 2012-13 – the last time they lifted the title.
Southampton's fourth consecutive Premier League defeat is also their biggest ever away loss in any competition.
United's efforts to share the goals around, with only Martial hitting a brace, means they are the second side to have seven different scorers in a Premier League match following Chelsea against Aston Villa in December 2012.
Ole Gunnar Solskjaer has seen his side utterly transform their home performances. They won only one of six at Old Trafford at the start of this league season, scoring three times. A run of four wins out of five, with one defeat, has yielded 19 goals.
The late flurry was aided by Bednarek adding a red card to his own goal, while it could have been so different were it not for Jankewitz's rash tackle. The teenager is the first player to be sent off on his first Premier League start since Serge Aurier for Tottenham in September 2017 and the fourth man to be dismissed inside two minutes in a Premier League game.
Wolves 2-1 Arsenal: David Luiz and Leno leave Arteta's men short
Arsenal took a deserved lead at Molineux through Nicolas Pepe, who now has three goals in his past four league starts – as many as he managed on his previous 16 starts.
Mikel Arteta says he will appeal David Luiz's punishment but the Brazilian defender's foul on Willian Jose means he has been sent off three times and conceded six penalties since his Arsenal debut in August 2019, more than any other player in the division during that time.
Ruben Neves converted from the spot before fellow Portugal midfielder Joao Moutinho hammered in a fabulous 30-yard effort. Very much a collectors' item, it was the first home goal of his Wolves career at the 61st attempt.
When Leno charged from his area to handball in a wretched misjudgement, Wolves' first league double over Arsenal since 1978-79 was virtually assured and the Germany international became the second Gunners keeper to be sent off in the Premier League – and the first since David Seaman against West Ham back in 1993.
Whether largely down to indiscipline or misfortune, Arsenal have been shown nine red cards since Arteta took charge on Boxing Day 2019 – six more than any other side.
Sheffield United 2-1 West Brom: Blades sharpen survival chances
Bottom club Sheffield United are now just a point behind West Brom in 19th, even though they fell behind to Matt Phillips' close-range finish before half-time.
Phillips has now found the net in each of the past 13 seasons in English league football, a run that goes back to 2008-09.
Jayden Bogle brought the hosts level before captain Billy Sharp stepped up to net another crucial goal.
Since Chris Wilder's first game in charge of United in August 2016, Sharp has scored 76 goals in all competitions – 44 more than any other Blades player during that period.
Sam Allardyce's much-vaunted reputation for making his teams hard to beat is not doing West Brom much good at the moment. The Baggies have conceded 26 goals in nine Premier League games under the ex-England boss, as many as they let in during 13 matches under Slaven Bilic this term.
Newcastle United 1-2 Crystal Palace: Eagles soar clear of trouble
Newcastle remain eight points above the drop zone but are now seven shy of Palace, despite enjoying a dream start.
Jonjo Shelvey's long-ranger after 71 seconds was the quickest goal the Eagles have conceded in a Premier League match since Ian Taylor scored for Aston Villa inside a minute in March 1998.
Roy Hodgson's side had not won away from home after conceding first since overcoming West Ham in October 2019, drawing two and losing 12 of such games since.
But Jairo Riedewald's venomous hit saw them level in style as he ended a run of 13 games without a goal in the Premier League.
Gary Cahill then became Crystal Palace's oldest ever goalscorer in the Premier League at 35 years and 45 days. He is also the oldest Englishman to score in the Premier League at St James' Park since Alan Shearer last did so.