A much-changed Albion side gave Mikel Arteta’s side some anxious moments, but ultimately they couldn’t find that cutting edge – the story of so many games this season – and Lacazette’s strike in the second half gave the visitors a deserved win.
Arsenal, meanwhile, only made one change from their impressive win over Chelsea at the weekend – with Pierre Emerick Aubameyang starting in place of Lacazette.
Seagulls start well
Despite an unfamiliar line up – without a recognised forward – it was Brighton who created the better chances in the first half and the Seagulls started with plenty of energy.
There was an early half chance for Ali Jahanbakhsh but he fired Bernardo’s low cross over the top at the front post before Yves Bissouma’s cross picked out Dan Burn, but his looping header went over Bernd Leno’s goal.
Arsenal then had a good opportunity to test Rob Sanchez when the impressive Bukayo Saka was fouled just outside of the area, but Granit Xhaka fired the resulting free-kick narrowly over the bar.
Brighton upped the pressure, and had their best chance of the first half in the 36th minute. Mac Allister had fired just off target after Mohamed Elneny conceded possession before the Seagulls worked the ball from right to left. Bernardo teed up Jahanbakhsh and his powerful low drive forced Leno into a smart save low to his right.
There was a lively start to the second half, with incidents at both ends of the pitch.
The VAR checked for a Brighton penalty a minute after the restart after Lewis Dunk went down under a challenge from Elneny as he attacked a loose ball from a corner, before Sanchez produced a superb save to deny Aubameyang when the Arsenal skipper looked favourite to turn Saka’s low cross in from point-blank range.
Arsenal were much improved after the break, and suddenly were breaking forward with pace and purpose. Gabriel Martinelli was only just off target with a curling effort from 18 yards before Aubameyang cut in from the right, but only to see his effort drift wide of the far corner.
The Seagulls looked to regroup, and after 64 minutes Bissouma’s pass released Propper into the box, but his low drive was saved by Leno at his near post.
A minute later, however, Arsenal broke the deadlock. Sako breezed past Burn and found Lacazette in space 15 yards out, and he had time to take a touch before driving it low past Sanchez having come on a matter of seconds earlier.
Potter reacted by sending on Neal Maupay, Solly March and Leandro Trossard in a bid to try and rescue something from the game in the closing stages, but although the Seagulls often got into some promising positions, the final ball was missing against a tight Arsenal defence who held out for the win.