Arsenal struck twice late on to become the first English team to beat AC Milan in the San Siro and deservedly reach the last eight of the Champions League.
Arsene Wenger's side produced a virtuoso display but had to wait until the 84th minute before Cesc Fabregas fired in a low 30-yard finish.
Emmanuel Adebayor then turned in Theo Walcott's cross in injury time to send the holders crashing out.
Fabregas hit the bar in the first-half as Arsenal dominated almost throughout.
It was another famous Champions League win for Arsenal in Milan, following on from their famous 5-1 win against Inter in November 2005.
Milan opened brightly, with Fabregas clearing off the line from Paolo Maldini's header at the near post, but once Arsenal found their stride they controlled the first 45 minutes in composed fashion.
Fabregas dictated affairs in midfield to even outshine Kaka, but the Brazilian escaped to set up Alexandre Pato after 18 minutes, only for the youngster to finish tamely.
Arsenal were understandably furious after 32 minutes when Alexander Hleb was shown the yellow card for diving by Austrian official Konrad Plautz, even though he had been blatantly upended on the edge of the area by Alessandro Nesta.
And they were frustrated seconds later when Fabregas saw a rising drive from 20 yards rebound off the crossbar with Zeljko Kalac well beaten.
Arsenal could have taken the lead seconds after the break when Fabregas's corner landed at the feet of Philippe Senderos, but he could only send an instinctive finish straight at Kalac.
Emmanuel Eboue then wasted another glorious chance as Andrea Pirlo sent an awful pass straight to Adebayor. He found Eboue in space only 10 yards out, but he shot wastefully wide.
Milan had faded as an attacking force, but Pirlo kept Manuel Almunia on his toes with a dipping free-kick that was turned around the post by Arsenal's keeper.
Wenger made a bold substitution with 20 minutes left, sending on Walcott for Eboue.
And within four minutes he almost set up a goal, only for keeper Kalac to stretch out a leg and block his cross with a collection of Arsenal players waiting to pounce.
Arsenal almost paid the price for their profligacy in front of goal with 12 minutes left when Pato was only inches off target with an angled shot that took a deflection off Senderos.
Arsenal finally got the goal they so richly deserved with six minutes left when Fabregas advanced and sent a low shot into the corner past the despairing dive of Kalac.
And a stunning performance got the final flourish it deserved when Walcott crossed perfectly for Adebayor to turn in at the far post.