LONDON (REUTERS)- Arsenal missed their chance to go back to the top of the Premier League after being forced to play with 10 men for much of the game against London rivals Chelsea on Sunday (Jan 24).
Arsenal's German defender Per Mertesacker was sent off after 18 minutes for denying a goalscoring opportunity to Diego Costa, who scored the only goal five minutes later from a cross by Branislav Ivanovic.
The result preserved the defending champions' unbeaten record under experienced Dutchman Guus Hiddink, who took over as interim manager last month following Jose Mourinho's sacking.
They remain a bogey side to Arsenal, who have not beaten them in the last nine league games, failing to score in the last six.
Arsene Wenger's side were left in third place, level on points with Manchester City but three behind leaders Leicester City, who beat Stoke City 3-0 on Saturday.
Chelsea moved up to 13th, as high as they have been since beating Arsenal 2-0 at Stamford Bridge in September. On that occasion, two Arsenal players were sent off - although the red card to defender Gabriel was later rescinded.
Costa proved the key figure on Sunday before making way for substitute Loic Remy midway through the second half.
Arsenal, who took off striker Olivier Giroud after the sending-off in order to bring on Gabriel in defence, improved in the later stages, when Alexis Sanchez came on as a substitute, but they managed only one shot on target.
As Chelsea's captain John Terry claimed, his team were on top even before the sending off.
Terry insisted that reaching the top four to qualify for next season's Champions League was still not out of the question despite a 14-point gap with fourth-placed Tottenham Hotspur.
"Everyone's beating everyone and if we can put a run of games together, we are not writing anything off," he told Sky Sports.
Hiddink was more circumspect.
"It's a big gap," he said. "But I want to see ambition always, whether you can (do it) or not. "When you come here, you have to take the initiative and I'm proud of the guys."
Wenger felt Arsenal should have had a draw despite making so few chances but said they are still very much in the title race. "It will be very tight until the end," he told Sky Sports.