Arsenal achieved their first Premier League victory over Jurgen Klopp's Liverpool as they came from behind to win 2-1 at Emirates Stadium.
The champions took the lead on 20 minutes after Andrew Robertson burst down the left wing and squared for Sadio Mane, who side-footed in.
But the Gunners were back on level terms when Alexandre Lacazette pounced on a mistake by Virgil van Dijk, rounding Alisson and slotting home on 32 minutes.
A minute before the break, Alisson gave away possession and was punished clinically by Arsenal as Reiss Nelson scored his first PL goal with a composed finish.
Liverpool pushed for an equaliser after half-time, Mohamed Salah's shot flying just over the bar, Van Dijk's far-post header going wide and Mane missing a chance in the closing stages.
But Mikel Arteta's men held on for a notable victory, their first over Liverpool since 2015, and might have made it more comfortable when Joe Willock missed a late chance.
Arsenal stay ninth on 53 points, one point behind Sheffield United while Liverpool are top with 93. They now cannot reach the 100-point mark this season.
Arsenal: 21 Jul v Aston Villa (A)
Liverpool: 22 Jul v Chelsea (H)
Referee: Paul Tierney. Assistants: Dan Cook, Simon Long. Fourth official: Graham Scott. Replacement official: Michael George. VAR: Craig Pawson. Assistant VAR: Stephen Child.