Palermo have opened up a 2-0 half-time lead over AC Milan in their Serie A clash to stun the home supporters at the San Siro.
The visitors should have been ahead inside the second minute when Franco Vazquez forced his way into the box, but Diego Lopez managed to get a vital hand on the midfielder's low strike.
Milan improved as the first half progressed, and went close to breaking the deadlock when Andrea Poli struck a shot wide after being played through by Jeremy Menez's flicked pass.
Fernando Torres, who started in attack for the hosts following recent criticism of his performances, then headed just wide of the target from a dangerous free kick.
An early injury to Alex had forced Filippo Inzaghi to bring on Cristian Zapata, and the defender made the worst possible contribution as he handed the lead to Palermo by heading into his own net as he looked to clear a corner.
Milan struggled to respond to the setback, and they were punished for more sloppy defending as Paulo Dybala stormed clear and fired into the top corner moments after being denied by Lopez, who was unable to offer any resistance as the visitors deservedly doubled their advantage.