But Koscielny got there first, heading the ball down.
Within six seconds, Arsenal had won back possession.
After winning the ball, the Gunners didn't immediately launch an attack. Instead, they patiently built up their play from the back.
Goalkeeper Fabianski, center-backs Koscielny and Subotic, and holding midfielder Alexandre Song exchanged a series of one-touch passes, forcing the Boca Juniors defensive line to retreat again and again.
The ball moved into midfield and was switched to the right flank.
Lichsteiner moved up and passed it to Walcott.
But they couldn't find a way through on the right, so the ball was passed back to Wilshere, who then laid it off to Arteta.
Arteta passed it forward to Wang Shuo, who had dropped back. Wang Shuo played a one-touch pass out to Hazard on the left and immediately made a run forward.
Under pressure, Hazard couldn't get the pass off in time and was forced to play it back to Arteta.
