Arsenal slipped to sixth in the Premier League following a shock 2-1 loss to Swansea City at the Liberty Stadium on Sunday.
Although the Gunners were leading through a second half strike from Alexis Sanchez, two goals in quick succession from Gylfi Sigurdsson and Bafetimbi Gomis saw the Swans take all three points.
The match got off to a slow start with both sides looking very cautious and unwilling to take any risks.
There wasn't much action in the opening stages, with the only noteworthy incident being the Swans' penalty claim in the 20th minute.
The hosts appealed for a penalty after Calum Chambers appeared to have pushed Wilfried Bony inside the area but referee Phil Dowd waved away the protests and signalled for play to continue.
Jefferson Montero, whose speed caused a lot of problems for the Arsenal defence, soon created the first real chance of the game as he picked up Bony in a good position in the 36th minute.
The Ivorian striker immediately sent the ball to Marvin Emnes on the left but the Dutchman's effort went straight at Wojciech Szczesny.
Arsenal, who were very quiet for most parts of the first half, sprung to life during the final five minutes as Danny Welbeck forced former Gunner Lukasz Fabianski into a good save, before Aaron Ramsey's well-struck volley went narrowly wide of the post.
After the break, the Gunners started attacking as Sanchez and Alex Oxlade-Chamberlain became a constant threat to the Swans defence.
After a period of sustained pressure, the Gunners finally managed to crack the Swans' defence as Sanchez broke the deadlock in the 63rd minute.
A good attacking move from Arsenal saw Oxlade-Chamberlain charge down the middle and send the ball towards Santi Cazorla, who in turn picked out Welbeck down the right. The former Manchester United striker then set up Sanchez, who made no mistake in slotting the ball past Fabianski.
However, the Welsh side were not behind for long as Sigurdsson levelled the scores with a 25-yard free-kick in the 75th minute, after Kieran Gibbs brought down Modou Barrow outside the box.
Things went from bad to worse for Arsenal as the Swans took the lead after three minutes through Gomis.
Montero, after again getting the better of Chambers, whipped in a good cross towards Gomis, who rose above Nacho Monreal, to plant a perfect header past Szczesny, sealing all three points for Swansea.