Arsenal manager Arsene Wenger has warned his side against complacency after their 2-0 win at Celtic in the first leg of a Champions League qualifier.
A place in the Champions League group stage lies in reach and Wenger said: “We have a good advantage but it is 180 minutes and we are in front after 90.
“You want to play well for 180 and that is our purpose.
“We have to make sure we win the game at home, we have to take it seriously and it is a massive game.”
“It was a fierce battle,” added Wenger. “We dominated the game but Celtic were always fighting and counter-attacking and in the end, despite being in control, we scored two lucky goals. But yes, of course, we merited the good fortune.
“I concede that we were lucky with the goals but we had plenty of opportunity in the first 15 minutes of the second half.
“We needed a very strong Arsenal side to win the game.
“The crowd was up for it and the team was up for it and if it had been an average performance from Arsenal we would not have won the game.
“The atmosphere was better than the Premier League and people were fair.
“Celtic were organised and even at 2-0 they never gave up.”
Wenger admits he is surprised at how quickly Thomas Vermaelen has settled in to his Arsenal defence.
The Arsenal boss said: ”Yes, I am surprised but we saw that he had the physical strength and mentality to cope and when he was needed he came in.
”I believe he has a good mix of the physical and technical for a centre-back and it is interesting to have a left-footed player because he gives you angles for the pass which are very important for the midfielder.”