Arsenal went into the tie with a seemingly comfortable 3-0 lead from the first leg but the Gunners conceded twice within 70 seconds in the opening 45 minutes to put the game in major doubt.
However, a couple minutes after half-time, Sead Kolasinac calmed matters with an emphatic finish to dent Ostersunds’ momentum.The away side remained the better team and had chances to grab a third late on but Arsenal held on to move into the last-16.But Wenger was far from happy with his players and expressed relief at qualifying for the next round.
Wenger said: “We were not at the races in the first half, the second half was much better – we should have scored a few goals. Our energy was better.
“In the first half we were in trouble and in danger. We were complacent, we were open every time we lost the ball and had no idea when we had the ball. Overall we responded well and did the job.
“We prepared properly in a serious way. The fact we had won 3-0, that we have a big game on Sunday and that subconsciously people think they just have to turn up.
“It’s not like that, we played a good side.”