Krzysztof Piatek marked his first AC Milan start by scoring both goals as AC Milan reached the Coppa Italia semi-finals with a 2-0 win over Napoli on Tuesday.

New boy Piatek - signed by the Rossoneri from Genoa to replace the departed Gonzalo Higuain - quickly endeared himself to Milan fans, striking twice in the first half to become an instant hero with the San Siro faithful.

The Poland international had made his debut off the bench in the 0-0 draw between the teams last Saturday, yet his finishing abilities made sure there was no repeat of that Serie A stalemate.

Both times he capitalised on space available through Napoli's right channel; his opener was tucked home with finesse when clean through but his second was all about power, a right-footed rocket fizzing past visiting goalkeeper Alex Meret.

The striker had already slashed an ambitious first-time volley wide before he opened his Milan account 10 minutes into the tie, Diego Laxalt's hopeful long punt putting his team-mate in the clear.

Piatek – who had scored four goals for Genoa in his maiden Coppa Italia appearance, against Lecce in August – kept his cool to convert, opening his body up to bend a right-footed effort beyond Meret.

He doubled both his tally and Milan's lead 17 minutes later, only this time his attempt with the same foot came when he was going away from goal, Piatek cleverly keeping the ball away from Kalidou Koulibaly as he cut inside from Milan's left before unleashing a drive that flashed into the net.

Napoli, in contrast, struggled to create opportunities despite dominating possession. Lorenzo Insigne missed an excellent chance to equalise for the visitors soon after Piatek had broken the deadlock, carelessly sending a first-time effort straight at Gianluigi Donnarumma 

Alessio Romagnoli's block denied Arkadiusz Milik tapping home a loose ball following a corner after the break, with Milan holding firm to keep a clean sheet and become the first team through to the last four.

What does it mean? Milan continue to be up for the cup

Losing finalists in 2016 and 2018, Milan may hope this may be their year in the competition. Piatek's goals may be the added ingredient they need to lift the trophy for a sixth time, with boss Gennaro Gattuso a member of the team who last did so, back in 2003.

Piatek up and running for Milan

A reported fee of €35million was needed to bring in Piatek from Genoa, who made a healthy profit on a player they had only signed themselves in June. Still, the 23-year-old may just be the answer to Milan's scoring problems - they scored just 56 goals in Serie A last season - if he can build on a confidence-boosting brace.

Insigne off target as Napoli fall short

For a second successive season, Napoli's cup hopes came to an end at the quarter-final stage. Unlike the clinical Piatek, Insigne fluffed his lines in front of goal in the opening half, only locating Donnarumma after a cross had broken kindly into his path.

What's next?

Napoli will hope to bounce back from their Coppa exit when they host Sampdoria in Serie A on Saturday, with Milan in action the day after, travelling to take on Roma in a match with top-four ramifications.