Liverpool recorded their first away win over Arsenal since 2000 to heap more misery on the Gunners - who saw Emmanuel Frimpong sent off and lost injured centre-back Laurent Koscielny in a 2-0 defeat at Emirates Stadium.
Samir Nasri impressed for the Gunners, despite being expected to join Manchester City, but Arsenal's luck was out after Aaron Ramsey's own goal and a last-minute strike from substitute Luis Suarez handed the visitors victory.
Pure joy: Liverpool manager Kenny Dalglish celebrates as his side grab victory
MATCH FACTS Arsenal: Szczesny, Vermaelen, Koscielny (Miquel 15), Sagna, Jenkinson, Nasri, Walcott (Bendtner 80), Ramsey, Arshavin (Lansbury 71), Frimpong, Van Persie. Subs not used: Fabianski, Chamberlain, Chamakh, Miyaichi.
Yellow cards: Frimpong, Lansbury
Red card: Frimpong
Liverpool: Reina, Enrique, Agger, Carragher, Kelly, Henderson, Downing, Lucas, Carroll (Suarez 71), Adam, Kuyt (Meireles 71). Subs not used: Doni, Skrtel, Flanagan, Maxi, Spearing.
Yellow cards: Lucas, Carroll
Referee: Martin Atkinson
Arsene Wenger - who now has half his first-choice team out because of suspension or injury - must regroup his squad for next week's crucial Champions League play-off second leg in Udinese and the small matter of a trip to Manchester United.
Nasri - whose ?22million move to City is, according to reports on French TV, said to have broken down - did not applaud the crowd as the teams came out of the tunnel, and was then jeered by some sections of the Emirates Stadium faithful when his name was announced.
Liverpool showed early intent, as Dirk Kuyt - who netted a late penalty deep into stoppage time to earn a 1-1 draw here last season - drilled a low, angled drive goalwards.
New Arsenal captain Robin van Persie looked lively as he nicked the ball out on the right channel and floated over a cross which Martin Kelly stabbed behind for a corner.
Game over: Liverpool's Luis Suarez rolls home the simplest of shots to secure the points
On eight minutes, Frimpong was cautioned for squaring up to Jordan Henderson as the Liverpool midfielder tried to take a quick throw-in.
It never rains, but it pours: Emmanuel Frimpong was sent off as Arsenal's weaknesses were again exposed
Koscielny added to Wenger's defensive problems when he pulled up with what looked like a lower back injury on 14 minutes and had to be replaced by youngster Ignasi Miquel, the Spaniard making his Premier League debut.
Liverpool almost took the lead on 20 minutes when Andy Carroll's towering header at the far post brought a brilliant save from Wojciech Szczesny.
Gloomy afternoon: Arsene Wenger has that sinking feeling as Arsenal slump to defeat
The visitors were in full flight now, with Henderson sending a tame header straight at the Arsenal keeper following another quick break down the left.
Charlie Adam then tried an audacious chip from the halfway line, which had Szczesny backpedalling, but flew over the bar.
Not gone yet: Samir Nasri made a surprise appearance in the Arsenal line-up
Arsenal finally mounted a meaningful attack after 30 minutes when Frimpong's low drive from 20 yards was pushed wide by Jose Reina.
Nasri then showed what Arsenal would be missing when he picked up the ball in his own half, dashed forwards and turned Liverpool inside out before unleashing a 25-yard strike which curled past the post.
Pointing the finger: Referee Martin Atkinson has a word with Arsenal defender Thomas Vermaelen
As the heavens opened for the start of the second half, Liverpool continued to frustrate Arsenal.
The visitors broke quickly into the Gunners box on 55 minutes, with Carroll laying the ball back to Kelly - and his snapshot struck the outside of the post.
More problems: Arsenal defender Laurent Koscielny is helped off the pitch by medical staff after picking up a back injury
Arsenal eventually started to up the pressure, but lacked a decisive pass in the final third.
Andrey Arshavin turned Kelly and fed van Persie at the near post, but his goalbound flick was kicked behind by Reina.
With 20 minute left, Arsenal were reduced to 10 men when Frimpong was shown a second yellow card when he left his foot up in a 50/50 with Lucas, right in front of the referee.
Clash of the day: Liverpool's Danish defender Daniel Agger goes flying under a challenge from Frimpong
Liverpool snatched a fortunate lead on 78 minutes when as Suarez darted into the six-yard box, Miquel's clearance cannoned off Ramsey's chest and back over the keeper into the net.
A miserable afternoon for the Gunners was compounded in the final minute when Suarez tapped infrom close range following a quick counter-attack.
Try as he might: Theo Walcott has been given little opportunity to hit top gear
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