Arsenal's FA Cup title defense started with a 3-1 victory at home to Sunderland on Saturday at the Emirates Stadium.
Sunderland took a surprising lead in the 17th minute as Jeremain Lens capitalized on an error by Laurent Koscielny, but Arsenal drew level eight minutes later through Joel Campbell.
The hosts piled on the pressure in the second half and finally went ahead via substitute Aaron Ramsey in the 72nd minute. Olivier Giroud wrapped up the win three minutes later with Arsenal's third.
"It was a test for us to come from behind," Arsenal manager Arsene Wenger said, per BBC Sport.