Kevin-Prince Boateng scored the fastest hat-trick in 10 years and Mario Yepes notched a late winner as AC Milan came back from 3-0 down to beat Lecce 4-3 on Sunday.
Milan were in disarray during a calamitous first 45 minutes and came into the break 3-0 down following goals from Guillermo Giacomazzi, a Massimo Oddo penalty and Carlos Grossmuller.
But Boateng came off the bench to fire a 14-minute treble and Yepes headed home seven minutes from time to earn Massimiliano Allegri's team an unlikely victory.
"It was very important that we could win this game, it was unbelievable, we came back, I scored three goals," said man-of-the-match Boateng.
"It's a very good day for me, I will take this ball home and put it in an important place in my house.
"I was a bit injured on the knee and I think the coach wanted to give me a bit of a rest but we didn't play well in the first half so he told me to go out and try my best.
"I'm very happy we won the game because it hasn't been easy for us this season but this win shows we can come back and we worked very hard."
Without injured centre-back Thiago Silva and the returning Philippe Mexes on the bench the champions could not have missed the pair more as they were a defensive shambles in the first period.
Milan's backline was nowhwere to be seen after just four minutes as Giacomazzi managed to head home Grossmuller's cross from inside the six yard box, beating hesitant goalkeeper Christian Abbiati to the ball.
The second came from the penalty spot after Abbiati was adjudged to have brought down Daniele Corvia as Milan failed in their attempts to clear a corner.
Television replays suggested the referee got that decision wrong as Corvia was on his way down before any contact with Abbiati happened.
But up stepped Oddo, who was released by Milan in the summer, to smash the spot-kick high past his former teammate on the half hour.
Lecce added a third before half-time.
First Mark van Bommel lost out in a 50-50 challenge, then Yepes dived in when he should have stayed on his feet and finally Luca Antonini inadvertently teed up Grossmuller, who would otherwise have been in an offside position, to prod the ball past Abbiati.
Milan coach Massimiliano Allegri introduced Boateng at half-time alongside Alberto Aquilani and the move paid instant dividends.
When Lecce failed to clear a corner, Aquilani clipped the ball back into the danger zone where Boateng fired home left footed into the top corner.
Minutes later he took aim again, this time from outside the box, and sent a missile into the opposite top corner.
The Ghana international completed his 14-minute hat-trick when Lecce again failed to clear their lines and he fired home inside Benassi's near post from the edge of the six-yard box.
It was the fastest triple in Italy since David Trezeguet score a 10-minute hat-trick for Juventus 10 years ago.
The winner came in the dying moments as Lecce's frail backline crumbled again and Antonio Cassano lofted the ball to the back post where Yepes outjumped Christian Obodo.
Elsewhere Udinese went clear on their own at the top of the table with a 3-0 demolition of newly-promoted Novara.
Captain Antonio Di Natale scored a brace and Maurizio Domizzi added the third as the northerners opened up a two-point lead over Juventus.
Inter Milan won their second game in a row and start to edge clear of the relegation zone as Brazilian-born Italy international Thiago Motta scored the only goal in their 1-0 defeat of Chievo.
They remain fifth from bottom but are only five points off third and the final Champions League qualification spot.
That position is occuped by Cagliari, another surprise package, who held Napoli to a 0-0 draw, their fourth straight game without conceding.