Ismael Bennacer gave AC Milan a slim advantage in their all-Italian Champions League quarter-final against Napoli with the only goal in Wednesday's tight 1-0 first-leg win.

Algeria midfielder Bennacer lashed in the decisive strike five minutes before half-time of an engaging contest at a packed, loud and wet San Siro after Brahim Diaz and Rafael Leao combined brilliantly.

The 25-year-old's second goal of the season ensured Milan's second win over Italy's champions-elect Napoli in less than a fortnight and a narrow lead to defend at Stadio Maradona in Naples next week.

Napoli, who had Andre-Frank Zambo Anguissa sent off in the 74th minute, should have Victor Osimhen back for the second leg on Tuesday and without their star striker Luciano Spalletti's team got nothing despite having plenty of chances.

Milan goalkeeper Mike Maignan made a series of impressive stops, in particular during an early salvo from Napoli which led to four good opportunities in the opening quarter of an hour.

He also saved Milan late on when he clawed out Giovanni Di Lorenzo's effort just as the more than 70,000 home fans were celebrating victory.

But Bennacer's strike was just enough to give Milan hopes of their first Champions League semi-final since they were crowned kings of Europe for the seventh and most recent time in 2007.

That prospect will be all the more mouth-watering for Milan fans as their likely opponents would be local rivals Inter following their convincing win at Benfica on Tuesday.

The home fans had barely discarded their pre-match display which read "our destiny is in our hands" when Khvicha Kvaratskhelia wasted a great chance to give Napoli a stunning early lead.

Anguissa's low cross was dealt with terribly by the home defence but the home fans breathed a hge sigh of relief after Davide Calabria and Rade Krunic combined to block the Georgian winger's shot on the line.

Anguissa then had a powerful shot tipped over the bar by Maignan before Di Lorenzo headed a presentable Mario Rui cross over the bar as Napoli flooded towards the Milan goal in the opening minutes.

Kvaratskhelia, who was in the mood after disappointing in the league encounter, had a shot blocked after neat exchange with Eljif Elmas and Piotr Zielinski forced Maignan into another good stop with a rocket in the 12th minute.

Milan had barely been in the game up to that point but midway through he first half Leao reminded everyone he was there by fashioning a glorious chance through pure pace only to drag his shot just wide after bursting past Anguissa and Stanislav Lobotka.

And Bennacer put the hosts into the lead in the 40th minute after another brilliant piece of individual skill, this time from Brahim Diaz.

The Spanish international span beautifully in the midfield to break through pressure and fed Leao, whose first-time pass alluded Diaz and found Bennacer for a thumping near-post finish.

Simon Kjaer then smashed Bennacer's corner off the bar in stoppage time with a header which for a moment had fans celebrating before the ball bounced out just before the line.

Napoli began the second half in the same manner in which they started the first but again couldn't find their way past Maignan, who did brilliantly to tip Elmas' looping header over the bar.

And after Kim Min-jae headed straight at Maignan from the subsequent corner Napoli struggled hard to go into damage limitation mode once Anguissa was sent off for two quickfire bookings.

That didn't stop them having yet another chance denied by Maignan however as Di Lorenzo looked on in disbelief at the France goalkeeper, and the away side must be hoping that Osimhen will return for the second leg to offer a much-needed finishing touch. (AFP)