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.