Arsenal eventually saw off a stubborn Brighton to move back above Liverpool – for a few hours at least – at the top of the Premier League.
With Liverpool hosting Manchester United at 16:30 GMT, the Gunners returned to the summit thanks to Gabriel Jesus’ header and Kai Havertz’s late strike.
Arsenal dominated the first half without reward, but the tension eased when Jesus turned in after a corner.
The hosts were almost punished when Pascal Gross poked wide before Havertz sealed victory to spark joyous celebrations at a relieved Emirates Stadium.
The Seagulls, who were looking for a third successive league victory at Emirates Stadium, managed just one shot on target and drop to ninth place.
After a conservative first-half performance, Brighton offered more attacking threat in the final half an hour but anything other than a home win would have been scarcely deserved.
Arsenal had 25 shots in the match and almost added a late third through substitute Emile Smith Rowe.
“It was an incredible performance. It was a joy to watch from the start to the end,” said Arsenal boss Mikel Arteta, whose jubilant celebrations indicated the magnitude of the win.
“The way we played against a phenomenal Brighton side was incredible. We were patient, kept going, kept believing and got what we deserved.”