Despite Sporting’s previous home dominance, it was Arsenal who looked like the home team in the first half.
It took just seven minutes for the Gunners to take the lead, as Gabriel Martinelli tapped home Jurriën Timber’s pinpoint cross after a neat passing move.
Midway through the half, their advantage doubled with a similarly slick move on the right-hand side, which led to Bukayo Saka poking past Franco Israel and Kai Havertz eventually putting the ball in the back of the net.
Sporting’s only real chance fell to Geovany Quenda, whose fierce strike stung David Raya’s palm, but Arsenal netted a third before HT as Gabriel Magalhães headed in Declan Rice’s inswinging corner from close range.
Right at the start of the second half, it was the hosts’ turn to score from a corner. Hidemasa Morita forced Raya to parry away his powerful strike, and from the resulting corner, Gonçalo Inácio poked home Francisco Trincão’s flat cross at the near post - remarkably the 56th successive home game Sporting have found the net.
However, after their early dominance, Ousmane Diomande slid in and took out Martin Ødegaard in the box, with a penalty awarded to Arsenal in their first real attack of the half.
Saka stepped up and struck right into the bottom corner, leaving the goalkeeper no chance.
Sporting still showed a fighting spirit though, as Morten Hjulmand forced Raya to push his powerful drive wide, before Trincão’s deflected effort just dipped over.
However, the damage was done in the first half, and Arsenal even had time to add a fifth in the latter stages, as substitute Leandro Trossard headed in from close range.
Viktor Gyökeres was largely kept quiet all night, but did see his late strike brilliantly tipped onto the bar by Raya.
In the end, the Gunners ended a five-game winless streak away from home in the UCL in emphatic fashion, and also stretched their impressive unbeaten H2H record against Sporting to seven matches as a result.