LONDON • Arsenal manager Arsene Wenger dismissed suggestions that his side have a mental block against London rivals Chelsea, following a 1-0 home defeat that carried an air of deja vu.
Arsenal were bidding to return to the top of the Premier League table in Sunday's game, but they were left in third place after Per Mertesacker was sent off and Diego Costa scored to give Chelsea a clinical 1-0 victory.
Arsenal have not beaten Chelsea in nine league games but Wenger said that Mertesacker's 18th-minute dismissal, for a last-man foul on Costa, meant it was impossible to compare the game with previous fixtures.
"I think today (Sunday) was a special game. We played with 10 men, we were 1-0 down straight away. Normally you lose a game like that 3-0 or 4-0," he told reporters at the Emirates Stadium.
"When you have to chase the game, (there's) nothing more dangerous than being down to 10 men. Overall we come out with a lot of regret because we feel we couldn't play with our team.
Number of red cards Arsenal have been shown against Chelsea - more than against any other side.
Matches since Arsenal beat Chelsea in the league - the longest winless run Arsene Wenger has ever had against a single opposition side.
Minutes without a goal against the Blues - the Gunners' longest such run against any team in Premier League history.
The last 12 goals in this league fixture have all been scored by Chelsea.
"And looking at Chelsea today, I think there was a lot of room to beat them if we had played with 11 players."
Mertesacker was shown a straight red card for felling Costa after he had latched onto a through ball from Willian.
The Chelsea striker immediately made his side's numerical advantage count by converting Branislav Ivanovic's cross with a near-post volley in the 23rd minute.
Costa had goaded Gabriel into kicking out at him in September's reverse fixture, earning the Arsenal centre-back a red card, and Wenger told a TV interviewer: "He has got two (Arsenal) players sent off this season."
Addressing the print media shortly after, the Arsenal manager backtracked, saying that he had only been stating "facts", but maintained that referee Mark Clattenburg's decision had been "harsh".
Chelsea's interim manager Guus Hiddink said that Mertesacker's lunge had merited "a red card without any discussion".
Wenger reacted to Mertesacker's dismissal by sending Gabriel on for striker Olivier Giroud, which drew a chorus of boos from the home supporters.
But he was unrepentant, saying: "Do you want to make a poll for every decision to see who does what? I make the decision and for me it was a normal decision."
Unfortunately for the Gunners, it did not work out and they have failed to score in consecutive league games for the first time since August 2012.
They also failed to find the net at Stoke the previous week.
Arsenal, now three points below leaders Leicester City, host second-tier Burnley in the FA Cup at the weekend before resuming their title challenge at home to Southampton on Feb 2.
Wenger said that time was on his team's side.
"There is a long way to go," said the Frenchman, who welcomed Alexis Sanchez back after the player spent two months out with a hamstring injury.
"What we take from today is that we are disappointed, but have a lot of positives from our attitude and spirit."