Pato scored an extra-time winner as Milan edged past Novara 2-1 in their Coppa Italia last-16 tie at the San Siro.
Milan will meet Lazio in the Coppa Italia quarter-finals after a 2-1 extra-time victory over Novara at San Siro on Wednesday.
A sensational first-half strike from teenager Stephan El Shaarawy appeared to have sent the hosts through, but Novara midfielder Ivan Radovanovic converted a last-gasp free-kick to restore parity and ensure there would be a further 30 minutes of action.
But the underdogs’ brave efforts eventually proved futile as super-sub Alexandre Pato netted a 100th-minute winner to secure safe passage to the next round.
Milan boss Massimiliano Allegri elected to go with something of a second string line-up, resting the likes of Pato, Zlatan Ibrahimovic, Robinho, Thiago Silva and Ignazio Abate. He handing starts to Alexander Merkel – having returned to the club on-loan from Genoa on Tuesday – as well as veteran Filippo Inzaghi and El Shaarawy.
And after a slow first quarter of an hour in which the hosts held significant territorial control without threatening, Inzaghi should have given his side the lead when he headed Luca Antonini’s teasing cross wide from just six yards.
Almost immediately, Novara struck back at the other end, when Simone Pesce forced a smart save from Marco Amelia with a powerful shot from distance.
However, Milan would eventually take the lead their play merited in the 24th minute, after El Shaarawy drifted inside Paolo Dellafiore and unleashed a stunning, swerving strike from 22 yards which crashed into the net past Novara goalkeeper Alberto Fontana.
Italy Under-21 international El Shaarawy was proving to be a constant thorn in Novara’s side, and he was only denied a second goal by superb goalkeeping from Fontana eight minutes before the break.
Milan re-assumed control after the break, with El Shaarawy remaining a hugely influential figure. But the hosts’ attacking moves would, time and again, break down in and around the final third.
One the rare occasions everything did open up, Urby Emanuelson, who was occupying the playmaker role, proved wasteful.
On the hour mark, the Dutchman dragged a woeful shot well wide of Fontana’s left-hand post, to Antonio Nocerino’s visible frustration. Seven minutes later, he side-footed weakly into Fontana’s arms from close range.
Milan’s failure to put the game to bed was eventually punished in the 89th minute when Radovanovic reached a free kick rolled to him by Pesce and rifled a low shot through a ruck of players and into Amelia’s bottom right-hand corner, sending the tie to extra-time.
The additional time eventually burst to life in the 100th minute as Milan retook the lead, thanks to wonderful link-up play between Brazilian substitutes Robinho and Pato.
Pato fastened onto a magnificent flicked pass from his compatriot before touching the ball over the advancing Fontana and rolling into the net to make the score 2-1. It turned out to be the winning goal.
The same opponents will again square off on Saturday, this time in Serie A
The quarter-final tie between Lazio and Milan will be played on Thursday, January 26.