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Arsenal were in complete control, and the only surprise was that it took the Gunners until the 22nd minute to extend their lead - and it was a gift. Cologne's defeat in Belgrade makes it likely both Arsenal and Red Star will qualify for the knockout phase with something to spare.
Nearly immediately after that in the ninth minute, Wilshere played a one-two with Giroud to beat three defenders and then square a cross towards Walcott, who after watching Denis Scherbitski save his header, routinely finished the rebound.
It is clear where Arsene Wenger's priorities lie this season, considering the weakened squad that he has taken out to Belarus, but nothing less than a win will do for Arsenal.
Romelu Lukaku scores twice as Man United ease past CSKA Moscow
The three players out of contention to feature against CSKA Moscow are Marouane Fellaini , Michael Carrick and Phil Jones . While the Red Devils were beating Basel 3-0 at Old Trafford , the Russians won 2-1 away to Benfica in Portugal.
Theo Walcott bagged a first-half brace. However, Scherbitski did make a fabulous, fingertip save to deny Walcott his third - a fig leaf for a awful display.
Walcott made it 2-0 midway through the first half after an terrible error by BATE goalkeeper Denis Scherbitski, who miscued a clearance straight to the England forward.
However, three minutes into the second half, Arsenal netted their fourth thanks to a penalty from Giroud, who sent the ball into the bottom corner after Stanislaw Drahun was harshly adjudged to have fouled Shkodran Mustafi.
Dragun was booked for something we aren't quite sure of, and Giroud stroked home the penalty for his 100th Arsenal goal.