Robin van Persie and Emmanuel Adebayor both scored twice as Arsenal ultimately cruised to a 4-0 victory over 2004 winners Porto at Emirates Stadium.
Arsenal were given a few early scares by Porto before making the breakthrough on 31 minutes thanks to Van Persie's near-post finish.
Adebayor headed home a second goal on 40 minutes and, three minutes after half-time, Van Persie weighed in with his second of the game.
Togo striker Adebayor emulated Van Persie's brace on 71 minutes by converting from the penalty spot after Nicklas Bendtner had been brought down.
