Serie A champions-elect Napoli dominated early on - but Milan won a penalty with one of their first attacks, although Olivier Giroud's spot-kick was saved by Alex Meret.

The veteran Frenchman got the opening goal, though, to make it 2-0 on aggregate when he tapped in following a sensational 70-yard run by Rafael Leao to set him up.

Napoli were then gifted a way back into the game when Fikayo Tomori handled in the box, but visiting keeper Mike Maignan saved Khvicha Kvaratskhelia's penalty.

They did eventually score, through a Victor Osimhen header with seconds remaining in the match - and there was not enough time to create another chance.

Napoli, who are 22 points clear of Milan in the league table, have lost form at a critical time and failed to take a host of opportunities, with 39 efforts across both legs.

Can Milan go all the way?

Milan, soon to be deposed by Napoli as Serie A champions, were seconds away from keeping a remarkable six consecutive Champions League clean sheets.

But they will not worry too much about that as they celebrate their best European season for 16 years.

Stefano Pioli's side have clearly focused on this competition, having rested all 10 outfield players in last weekend's Serie A draw with Bologna.

The Rossoneri seem to have the number of Napoli too, with two wins and this draw against the same team in April. They won 4-0 on their league trip to Estadio Diego Armando Maradona earlier this month and beat them 1-0 in last week's first leg in Milan.

They rode their luck somewhat in the early stages, although captain Davide Calabria did brilliantly to control Napoli winger Kvaratskhelia.

They were awarded the penalty when Mario Rui caught Leao, but Giroud was denied by Meret in Milan's first shot of the game.

But the 36-year-old made no mistake after Leao's brilliant run that had vibes of George Weah's solo goal in 1996 for Milan against Verona.

They held off Napoli's attempted comeback with determined defending and, unless Benfica turn things round on Wednesday, will face Inter in a Champions League semi-final derby.

Napoli stumbling at terrible time

Luciano Spalletti's Napoli are close to a first Serie A title since 1990 and the days of Diego Maradona, and surely cannot let a 14-point lead over second-placed Lazio slip with eight games left.

This was their first European Cup quarter-final and expectations were high.

But the top scorers in this season's Serie A and Champions League are not finishing the campaign as they would have hoped.

They had only lost three games in all competitions before April. Had the returning Osimhen not headed in late on for a second-leg draw, they would have lost as many against Milan in this month alone.

And they also had Rui and Matteo Politano taken off with first-half injuries.

Kvaratskhelia, despite being handled well by Calabria, was their most lively player, but missed several efforts including the penalty as the Georgian sensation's first Champions League season ended in disappointment.

Now their attention will turn back to domestic competition and making sure they get the four wins they need to clinch the crown.