Napoli shocked Inter Milan at home following a 1-0 win over the hosts in the first leg of the Coppa Italia semi-final encounter on Wednesday night.
Fabian Ruiz netted the only goal in second half that saw Napoli hold an advantage over Inter Milan ahead of the second leg.
Inter Milan started on the front foot, working it forward patiently, with Victor Moses almost getting in down the right though Napoli cleared heir lines.
There was an early booking for Skriniar as he was forced to cover and in the process, he clattered into Elmas, who stayed down and needed treatment.
Milan's huge chance came just before half time. Padelli produced a massive save as he rushed out of his line to deny Mertens from a tight angle. Napoli recycled possession with Zielinski getting a shot off, but he sent it wide.
In the second half, Milan picked from where they left but found themselves trailing after Ruiz Fabian's brilliant strike. It was truly out of the highest order as the Spaniard picked out the top-left corner with a superb striker from the edge of the area after Napoli countered. The move looked to have broken down, but the midfielder had produced a moment of magic.
The second leg of the competition will take place in the first week of March.