Arsenal boss Arsene Wenger refused to criticise his players after defeat at Tottenham.
Spurs went seven points clear of Arsenal with the win.
Wenger said: "It happened to us many times this season and only in big games. It's difficult to say why, there's no common thing, in all the games there is a different problem. But after you make it difficult for yourself. I cannot fault the attitude or the effort that the team produced, or the spirit the team has shown, but you give yourself a mountain to climb every time in a game of that magnitude."