Arsenal rekindled their bid for a first Premier League title in 20 years by beating leaders Liverpool 3-1 at the Emirates as Chelsea succumbed to another embarrassing defeat, 4-2 at home to Wolves, on Sunday.
Arsenal dominated in the opening stages and were reward with the opening goal. Bukayo Saka stroked home after Alisson Becker denied Kai Havertz.
Liverpool did not have a shot on target in the first half but levelled, after a defensive mix-up, when Gabriel Magalhaes turned Luis Diaz's cross into his own net.
The visitors repaid the favour after the break as Alisson collided with Virgil van Dijk as he rushed out from his goal and presented Gabriel Martinelli with the simple of tasks to roll into an empty net.
Liverpool were left with a mountain to climb when Ibrahima Konate was sent off for a second yellow card after fouling Havertz.
Leandro Trossard then took advantage of the space on the right side of the Liverpool defence as he surged forward and blasted beyond Alisson.
Mauricio Pochettino apologised to the Chelsea fans after Matheus Cunha's hat-trick handed Wolves their first victory at Stamford Bridge since 1979.
The Blues were booed off by furious fans after dropping into the bottom half of the table.
Cole Palmer put Chelsea ahead with a composed angled finish from Moises Caicedo's defence-splitting pass in the 19th minute.
But Chelsea's lead lasted just three minutes, with Cunha's shot taking a hefty deflection off Thiago Silva to leave Blues keeper Djordje Petrovic wrong-footed.
Pochettino wore an exasperated look in the 43rd minute when Rayan Ait Nouri's shot deflected in for an own goal off Chelsea defender Axel Disasi.
The already fraught atmosphere turned even more toxic in the 63rd minute as Pedro Neto teed up Cunha to drive in Wolves' third goal.
Cunha's 82nd-minute penalty, awarded when he was fouled by Malo Gusto, capped a miserable afternoon for Pochettino, who took no consolation from Silva's close-range finish in the 86th minute.
Manchester United climbed into sixth with a 3-0 win over West Ham as Rasmus Hojlund and Alejandro Garnacho gave the Red Devils a glimpse of a bright future.
Hojlund failed to score in his first 14 Premier League games but now has four in four as he marked his 21st birthday with a thumping strike to open the scoring.
Garnacho's deflected effort made it 2-0 early in the second half before the Argentine rounded off the scoring six minutes from time.
Nottingham Forest moved two points above the relegation zone after a 1-1 draw at Bournemouth. (AFP)