Swansea City leapfrogged Arsenal into fifth place in the Premier League table as they came from behind with two late goals to claim a memorable win over Arsene Wenger's men at the Liberty Stadium.
Alexis Sanchez helped Arsenal take the lead when the Chilean forward finished from close range after an excellent run and pass from Danny Welbeck. But a stunning free kick from midfielder Gylfi Sigurdsson and a fine header from substitute Bafetimbi Gomis sealed Swansea's victory.
For Wenger's side defeat caps a miserable week after their Champions League collapse against Anderlecht on Tuesday, in which they threw away a three-goal lead to draw 3-3, The BBC reported.
There were some nervy moments from Arsenal's defenders, with Calum Chambers surviving a Swansea penalty appeal after appearing to shove Wilfried Bony to the ground inside the area.
Clear scoring opportunities were at a premium in the first half as two slick but congested midfields cancelled each other out.
Arsenal did not manage a shot on target until a minute before half time, as Welbeck combined well with Sanchez before his effort was palmed away by former Arsenal stopper Lukasz Fabianski.
Also Read
The second-half saw some strikes by Arsenal on Swansea's goalpost but only Sanchez managed to put the ball past their keeper. Arsenal seemed in control at this point but, within 15 minutes, the match was completely transformed.
Swansea were awarded a free kick 25 yards from goal after Kieran Gibbs was booked for fouling the hosts' debutant Modou Barrow and Singurdsson made the most of it as he curled an unstoppable shot into the top corner.
Arsenal barely had time to register the blow of Sigurdsson's leveller by the time Swansea took the lead less than three minutes later through Gomis.
Swansea manager Monk admitted that it's about belief, adding that they talked about belief before the game, about how good they have been and how good Swansea can be.
Meanwhile, Arsenal boss Wenger admitted that it's disappointing to throw a game away like they did, adding that they were 1-0 up and had to be tight defensively and wait for that second chance, but agreed that one has to credit Swansea who didn't give up.