London: Arsenal conceded an injury-time own-goal to give Swansea a 2-2 draw on Tuesday and fall further behind in the Premier League title race.
Coming off a 6-0 drubbing at Chelsea on Saturday, Arsenal endured another demoralizing result after rallying for a 2-1 lead - only to concede a fluke equalizer.
Per Mertesacker slid in front of Leon Britton to clear a dangerous ball, but it bounced off goalkeeper Wojciech Szczesny onto Mathieu Flamini and into the net.
Arsenal had trailed after Wilfried Bony put the visitors ahead with a header in the 11th minute. But substitute Lukas Podolski equalized in the 73rd and then set up Olivier Giroud for the second less than 70 seconds later.
However, the late equalizer left Arsenal six points behind leader Chelsea in fourth place. That last Champions League spot now suddenly looks vulnerable as well, with Everton six points behind with a game in hand as Arsenal look increasingly likely to finish yet another season fighting for fourth place.
"This result tonight hurts us a lot," Arsenal manager Arsene Wenger said. "The way it happened of course is more frustrating. ... We made a mistake on the second goal, it was not needed."
Swansea even left feeling aggrieved after referee Lee Probert blew for full time just as Jonathan de Guzman was racing clear on goal with a chance to net a winner.
"For me, it's a very poor decision," Swansea manager Garry Monk said. "It's definitely going to be a shot on goal. ... Whether he scores that one or not, I don't know."
Arsenal started ambitiously and seemed eager to turn the page on the Chelsea embarrassment. However, the home side was caught on the counterattack when Neil Taylor sent a ball into the area and Bony beat defender Thomas Vermaelen in the air to head the opener at the near post.
Arsenal dominated possession for much of the rest of the game but failed to create any clear-cut chances until it netted two goals in the space of 70 seconds midway through the second half. First, Kieran Gibbs cut into the left side of the area and squared for Podolski, who slotted in the equalizer. Shortly after the restart, Swansea gave the ball away and Podolski turned provider as he raced down the left flank and crossed for Giroud, who couldn't miss from close range.
Arsenal, which had been booed off the pitch at halftime, seemed to have turned things around only to concede the nearly comical equalizer.
"We just wanted to win the game without pushing any more forward, and a mistake happened unfortunately," Wenger said. "The result is very disappointing but the spirit we put in and the effort we put in was great. We have to take it on the chin."
Gibbs and Alex Oxlade-Chamberlain both started for Arsenal despite the red-card debacle against Chelsea, when Oxlade-Chamberlain handled in the area but Gibbs was mistakenly sent off instead. The red card was transferred to Oxlade-Chamberlain by the Football Association on Monday but then rescinded after it ruled that he did not prevent a clear goalscoring opportunity.
Sweden midfielder Kim Kallstrom, who was signed on the last day of the January transfer window only to be ruled out with a back injury a day later, made his debut as a substitute after Arsenal's second goal.