Liverpool's Premier League lead was cut to seven points by Arsenal and Chelsea after the Reds conceded a 90th-minute equaliser in a thrilling 3-3 draw at Newcastle on Wednesday.
Chelsea thrashed 10-man Southampton 5-1 to go second on goal difference ahead of Arsenal, who beat Manchester United 2-0.
Mohamed Salah's second-half double was not enough to extend Liverpool's seven-game winning run in all competitions as they failed to win for just the third time in 21 games under Arne Slot.
The league leaders were forced to come from behind at St James' Park twice, as Alexander Isak blasted Newcastle into a 1-0 half-time lead.
Curtis Jones levelled before Anthony Gordon restored Newcastle's lead.
Salah twice converted Trent Alexander-Arnold assists to turn the game around, taking his tally for the season to 15 goals.
However, there was a late sting in the tale as a rare error from Liverpool goalkeeper Caoimhin Kelleher allowed Fabian Schar to squeeze in a late equaliser for the Magpies.
"He has done remarkably well for us and even today he was good. Unfortunately, he misjudged the situation," Liverpool boss Slot said of Kelleher's blunder.
Meanwhile, Arsenal took full advantage by inflicting Ruben Amorim's first defeat as Manchester United boss. Once again, the Gunners were able to rely on their prowess from set-pieces to get the job done.
Jurrien Timber broke the deadlock, heading in Declan Rice's corner nine minutes into the second half.
William Saliba did not know much about the second, as he diverted in Thomas Partey's header from Bukayo Saka's corner, but the Frenchman did not care as Arsenal had the breathing space they craved.
A fourth consecutive win in all competitions confirmed Arsenal's return to form and applied a little pressure on Liverpool.
"A special day – it's a joy to play in this stadium with that energy, it's something incredible," Arteta said. "We scored two set-pieces, but we could've scored from open play many more."
Amorim, meanwhile, said those set-pieces are what ultimately killed the game for United.
"They can put a lot of players near the goalkeeper, and it's almost impossible to fight for the ball," he said. "We already know we have to be better." (AFP)