Arsene Wenger believes his Arsenal side may have "switched off" towards the end of their victory over Crystal Palace as they escaped with a 2-1 win.
The visitors had eased into a two-goal lead at half-time courtesy of an early Santi Cazorla penalty and an Olivier Giroud strike just before the break.
But Palace rallied in the second-half and had Arsenal defending deep - with substitute Glenn Murray scoring a stoppage-time consolation before cracking a post with the last meaningful touch of the game.
Arsenal moved third with the win and, although Wenger praised the fighting spirit of his players, he conceded they suffered a lapse in concentration as Palace pinned them back in search of a point.
"Certainly they thought that it was done," he said of his players.
"We know in the Premier League that it's never done, especially at 2-0. With that ball on the post we were a bit fortunate.
"We can learn from every game. I believe that the players know that maybe they switched off a little bit too early. Overall I still must say that our central defenders played very well today against a very direct and a very physical game at the back.
"We missed goal number three and when they came back to 2-1 we were a bit lucky, a bit fortunate. We did well so overall I'm pleased to have won three points in a place like this. I feel quite strong and let's just continue to fight and be tight until the end."
Eagles boss Alan Pardew was left berating referee Mark Clattenberg as he felt Pape Souare's foul on Danny Welbeck that led to Cazorla's penalty occurred outside of the box - with Welbeck then offside in the build-up to Giroud's strike.
"The first goal was a mistake by Pape - he should do better, although it was tough on us because it looked like the incident was outside the box," he said.
"The second goal was offside. That call should have been made. A minute before half-time you've got to get that call right."
Despite the defeat, Pardew hailed the performance of his side as the best he has seen since taking over at Selhurst Park at the turn of the year.
"We took a tactical decision to take the game to Arsenal," he added.
"We continued with the game-plan and I was very pleased with the reaction. Its probably the best we've played since I've been manager.
"The chance when it hit that post and it fell in to the goalkeeper's hands summed our day up. I thought it was going to spin into the net.
"There was some great team play and probably the best players were on our team. But we've lost and sometimes that happens. Our final moment in that box needs to improve but we are not far away from being a decent team."