Arsene Wenger praised the character of his inexperienced players in a hostile environment at Red Star Belgrade as they took a step towards the Europa League last 32.
Olivier Giroud scored the only goal of the game with a stunning overhead kick moments after the hosts had been reduced to 10 men.
The 1-0 win keeps up Arsenal's perfect start to Group H as a spirited Red Star team hit the post in the first half and tested Petr Cech on a number of occasions before having Milan Rodic sent off in the closing stages.