The man advantage eventually paid off five minutes later as Jack Wilshere spearheaded a trademark Arsenal passing move which led to Olivier Giroud adjusting his body well to score an overhead kick, adding to his collection of spectacular goals.
This win was their third in as many Europa League games and a welcome lift after a disappointing defeat by Watford at the weekend.
In a ferocious atmosphere at the Stadion Rajko Mitic, in front of 50,000 fans, Arsenal made it three wins out of three in Europa League Group H.
Wenger's side take on Red Star Belgrade in the Europa League this evening. From the resulting corner Boakye headed against the crossbar.
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It marked her second public appearance in mere days, perhaps signaling an end to her severe and traumatizing illness. The royal couple met children helped by the charities, as well as Paddington star Hugh Bonneville .
The home side kept the pressure on, though, and Cech came to the rescue when he denied a swivelling snapshot from Nemanja Radonjic, who saw a follow-up attempt smothered by Nelson.
The second half was much the same. Milan Rodic was shown what seemed like a harsh second yellow card after going up for a header with Francis Coquelin.
Giroud got himself on the scoresheet with another sensational strike.
The Gunners have won both their group games in the competition so far and boss Arsene Wenger will want the record maintaining in Serbia tonight. Arsenal had a great chance to start the half, but Giroud couldn't finish off the great pass from Walcott.
- Theo Walcott has been directly involved in four goals in his last four European appearances for Arsenal (three goals, one assist).