Alexandre Lacazette scored 21 seconds after coming off the bench to give Arsenal a hard-fought 1-0 win over Brighton.
The striker collected Bukayo Saka’s cut-back with his first touch after replacing Gabriel Martinelli in the 66th minute at the Amex Stadium before composing himself and firing a clinical finish into the bottom corner.
The goal secured a second consecutive victory for Arsenal following their 3-1 win over Chelsea on Boxing Day, giving them back-to-back Premier League wins for the first time since their opening two games of the season.
But they were made to work for it by Brighton, who would have gone into the half-time break in front if not for the wasteful finishing of Alireza Jahanbakhsh and Alexis Mac Allister.
Arsenal looked transformed in the second half, however, going close to scoring on numerous occasions before Lacazette broke the deadlock, his goal moving the Gunners from 15th to 13th in the Premier League table and pushing Brighton closer to the relegation zone.
Mikel Arteta stuck with the young players who impressed against Chelsea as Martinelli, Saka and Emile Smith Rowe kept their places in the side, the only change seeing Pierre-Emerick Aubameyang replace Lacazette following his return from a calf injury.
Arsenal started the game confidently enough, but for all their improvement against Chelsea, there was a familiar lack of attacking thrust in the first half, with Aubameyang cutting an isolated figure.