Arsenal slipped to its sixth loss from 11 away matches in the Premier League on Sunday, outplayed 3-2 at Swansea despite Robin van Persie's 18th goal of the season.
Van Persie put the Gunners ahead after only five minutes but Swansea equalized 11 minutes later through a penalty by Scott Sinclair.
The Welsh side took the lead through Nathan Dyer in the 57th. Theo Walcott made it 2-2 in the 69th but the Swans hit back immediately when Danny Graham took advantage of some slack defending to hit a 70th-minute winner.
In its first topflight season since 1982-83, Swansea played about 100 more passes than Arsenal and dominated possession against what has long been one of the most attractive teams in the Premier League.
''We've got the players to play great football and we've shown today we can match one of the best teams in the Premier League - and at their style of football,'' Dyer said.
Thierry Henry came on as a substitute for Arsenal but could do little.
Arsenal stayed fifth in the standings, four points behind fourth-place Chelsea in the final Champions League berth.
Swansea is in 10th place, 10 points behind the Gunners but nine clear of the relegation zone.
''It was a great game for the spectators,'' Graham said. ''Two passing teams that like to play football. We did catch them napping. We're stood here with three points and we deserve them.''
Arsenal looked on course for a comfortable win when Van Persie put the visitors ahead in the fifth minute. Andrey Arshavin slipped a pass forward from the inside right channel for Van Persie to collect, cleverly delaying his shot to slip the ball between defender Steven Caulker's legs and over goalkeeper Michel Vorm from close range.
But Swansea trailed for only 11 minutes.
Aaron Ramsey brought down Dyer in the area and referee Michael Oliver awarded a penalty, which Sinclair sent past diving goalkeeper Wojciech Szczesny's left hand for an equalizer.
Walcott and Arshavin both shot over the bar at the start of the second half before Joe Allen stole the ball from Arsenal's Aaron Ramsey and picked out Dyer, who scored.
Walcott clipped the ball over Vorm to equalize, but Swansea substitute Gylfi Sigurdsson passed to Graham less than a minute later, giving the striker the chance to shoot past the hesitant Szczesny.
