Relegation-battlers West Brom inflicted a shock 5-2 defeat on 10-man Chelsea at Stamford Bridge while Manchester City extended their lead at the top of the Premier League with victory at Leicester.
Chelsea centre-back Thiago Silva was sent off for two yellow cards inside the opening half-hour as Thomas Tuchel's 14-match unbeaten start in charge was brought to a shuddering halt.
Christian Pulisic had given the hosts the lead in the 27th minute after Marcos Alonso's free-kick hit the post, before veteran Brazilian defender Silva saw red.
West Brom then turned the game on its head in first-half stoppage-time when Matheus Pereira scored twice in quick succession.
Callum Robinson made it 3-1 just after the hour, with Mbaye Diagne's smart finish extending the lead in the 68th minute.
England midfielder Mason Mount reduced the deficit with 19 minutes left, but Robinson tucked in a fifth for the Baggies during stoppage time.
West Brom's first win in four league games moves them to within seven points of 17th-placed Newcastle, who host Tottenham on Sunday.
Leaders Manchester City further extended their advantage with a 2-0 win at Leicester.
Fernandinho saw an early long-range effort disallowed, with veteran striker Sergio Aguero standing in an offside position and ruled to be in the eyeline of Foxes goalkeeper Kasper Schmeichel.
In the 23rd minute, Belgium midfielder Kevin De Bruyne struck the crossbar with a free-kick before Leicester striker Jamie Vardy had a goal ruled out for offside just ahead of the break.
Manchester City finally broke the deadlock shortly before the hour when Benjamin Mendy curled a shot into the corner.
With 16 minutes left, Gabriel Jesus, on his 24th birthday, sealed victory when he stabbed the ball in from close range after a cutback from substitute Raheem Sterling.
Pep Guardiola's men move 17 points clear of rivals Manchester United, who have played two games less, while Leicester remain third.
Saturday's late match saw Liverpool return to form with a 3-0 win at Arsenal.
The Reds, now mathematically unable to defend their title, had dominated the first half, but were unable to find the breakthrough.
Substitute Diogo Jota had not been on long when he headed in a deep cross from Trent Alexander-Arnold to finally put Liverpool in front in the 64th minute.
Mohamed Salah weaved into the Arsenal penalty area before slotting past Bernd Leno to double the lead four minutes later.
Jota added a third with eight minutes left as Liverpool climbed above West Ham into fifth, two points behind Chelsea in the battle for Champions League qualification.
Leeds beat bottom club Sheffield United 2-1 at Elland Road to move into the top half.
Jack Harrison gave the home side a deserved lead in the 12th minute when he knocked in Raphinha's cross at the far post.
The Blades hauled themselves level just ahead of half-time through Ben Osborn, his blocked shot ruled to have crossed the line.
Leeds were ahead again in the 49th minute when Harrison's low cross was diverted into the net by defender Phil Jagielka for an own goal.
Stuart Dallas went close to another goal for Leeds when his shot clipped the crossbar before Blades striker Rhian Brewster sent a curling volley just wide late on as visitors slumped to a third successive league defeat.
