Arsene Wenger was disappointed after his side gave away two soft goals in Arsenal's 2-1 defeat to Chelsea in the English Premier League.

Fernando Torres and Juan Mata scored from free kicks to give the Blues all three points, despite a wonderful goal from Gervinho.

"I feel we played against a good team, but we gave the game away," Wenger said. "They had three shots on target and scored two goals, from soft set pieces.

"Defensively we were just not at the level you have to be in a game like that, which is where we were punished today. For the rest, we have shown quality and spirit but we have to show more personality and authority on the goals we conceded."

Wenger said Arsenal were the better side, in both the games last week - Manchester City and Chelsea - but lack of concentration let them down, after all three goals conceded came from set pieces. "I would not say that, it is just on the day when you play at home you do not expect to concede two set pieces," he said.

"That puts us every time on the back foot. We played two big games in a week, and it is difficult.

"Every time you are behind in a big game you have 65 per cent of chances to win the game. We came back last week and did so again today, but then straight away gave away another goal again.

"It is impossible because you have to take all the risks and open yourself up. You play against good players and they can hit you on the counter-attack. That is where we were not at the (right) level."

Wenger decided to leave Per Mertesacker on the bench for the Chelsea game, preferring Laurent Koscielny, who was at fault for both the goals conceded. "That is a decision which was based on the opposition we played," the manager added. "You can say it was a wrong one maybe, but I believe (that statement) is a lowering the quality of the players who played, they are internationals.

"If you do not play Koscielny or Vermaelen and cannot win the game, you will ask me the same question."