First-half goals by record signing Mesut Ozil and in-form Frenchman Olivier Giroud, his sixth this season and coming a day after his 27th birthday, gave the Gunners their 10th successive win.
While they took a firm grip on their group with six points from two games, London rivals Chelsea got their campaign back on track, after an embarrassing opening home defeat to Basel, with a 4-0 rout of Romanian side Steaua Bucharest.
Elsewhere Barcelona have a firm grip on their group with maximum points after a 1-0 win over a gallant Celtic, who played the last half hour with just 10 men as captain Scott Brown was sent off.
Barca have a two-point lead over AC Milan, who face them next in a double header, after the Italian side salvaged a 1-1 draw in Amsterdam with a Mario Balotelli penalty four minutes into stoppage time.
Barca's Spanish rivals Atletico Madrid displayed the grittiness that their coach Diego Simeone displayed during his playing career to come back and beat Porto 2-1 away and top their group on six points, leaving them unbeaten on the field of play this season.
Arsenal hold a three-point lead over both Napoli and last season's beaten finalists Borussia Dortmund, who beat Marseille 3-0 and will provide a stern test for Wenger's men in the upcoming double header.
Wenger, though, was in raptures over his side's performance against Napoli.
"The first half was amazing, absolutely fantastic. Everything was in there. All that you dream to see when you come to watch football," Wenger said.