Arsenal opened the scoring after 58 seconds, Gabriel Martinelli sweeping home a perfect pass from captain Martin Odegaard, but Liverpool grew into the game and Darwin Nunez levelled in the 34th minute.
There was a lengthy break midway through the first half as Trent Alexander-Arnold received treatment for an ankle injury sustained in a tangle with Martinelli, and the England defender had to be replaced by Joe Gomez at halftime.
By then Arsenal were back in front, sweeping forward on the counter-attack as Martinelli turned provider, whipping the ball across the box for Saka to poke home a simple finish in first-half stoppage time.
A huge @Arsenal win 🔴#ARSLIV https://t.co/if55cZ9mkC
— Premier League (@premierleague) 1665336903000
Odegaard missed a golden opportunity to increase Arsenal’s lead after the break and two minutes later Diogo Jota found Firmino with a perfectly weighted through ball for the Brazilian to slot across goalkeeper Aaron Ramsdale and into the net.
Arsenal came blazing back and a wild series of shots and blocks ended in a penalty when Liverpool’s Thiago Alcantara was adjudged to have fouled Gabriel Jesus and Saka made no mistake from the spot to put his side 3-2 up in the 76th minute.
It was enough to seal a win that takes Arsenal back into first place on 24 points, one ahead of second-placed Manchester City after nine games.
Liverpool’s disappointing start to the season continued, and their second league defeat leaves them in 10th spot on 10 points from eight games.