Arsenal fell to a surprise 1-0 loss at Norwich on Saturday as the hosts picked up their first Premier League win of the season.
Arsene Wenger's team now trails leader Chelsea by 10 points, after Norwich captain Grant Holt capitalized on goalkeeper Vito Mannone's error in the 19th minute.
Mannone spilled a long-range shot by Alex Tettey and Holt was first to the loose ball to score for the third straight game.
Arsenal struggled to create clear chances, but threatened in the 86th when Mikel Arteta's powerful low shot was held by Norwich goalkeeper John Ruddy diving to his left.
Jack Wilshere was on the Arsenal team sheet for the first time after 14 months sidelined by knee and ankle injuries, but Wenger declined to risk using him as a substitute as Norwich tenaciously defended what has been a rare lead this season.
Arsenal, which had not lost at Carrow Road for 28 years, is in ninth place. Norwich is 15th, rising four places to escape the relegation zone.
Norwich started with a self-belief that belied recent heavy losses against Liverpool and Chelsea, and winger Anthony Pilkington fired a second-minute shot just wide of Mannone's right-hand post.
Arsenal responded with Lukas Podolski flashing a left-foot shot across goal, but the German forward was seldom on the same wavelength as the Gunners' midfield seeking him.
Norwich took the lead when Tettey was allowed space to advance and fire a low 25-meter (yard) shot which Mannone pushed into the path of Holt, who outpaced Per Mertesacker to the loose ball to score for the third straight game.
Arsenal seemed uneasy with Holt's bulky presence in the air, and the burly Norwich captain showed good footwork to clip a dangerous pass across the goalmouth.
Norwich wasted a chance to extend its lead in the 34th when defender Michael Turner found space from a corner but placed his header wide.
Arsenal's off-key first-half display was summed up by Gervinho's miskick when receiving a floated cross at the back post.
Olivier Giroud, who was roughly treated by Norwich's central defenders, also failed to connect cleanly six minutes into the second half when goalkeeper John Ruddy pushed a cross toward onrushing Arsenal attackers.
Arsenal sent on Alex Oxlade-Chamberlain to pep up the forward line but within seconds the speedy England winger was injured in a challenge by Sebastien Bassong and soon returned to bench, as Andrey Arshavin came on.
When Arsenal pressed, Ruddy was barely tested to save from Gervinho's header and Santi Cazorla's free kick.
As the game opened up, Holt twice ran clear from the halfway line, but fired his first shot wide then his tame chip was easily saved by Mannone.
Gervinho shaped to shoot in the 89th but Bassong stretched to block the ball, summing up Norwich's resolve.