Walter Mazzarri’s side failed to take advantage of their man advantage following Mathieu Flamini’s dismissal in the second half, recording a draw that maintains the four point lead over Milan in the race for second place.
Milan boss Massimilliano Allegri’s omission of Stephan El Shaarawy from the starting line-up came as a surprise, particularly with Mario Balotelli suspended for the game.
The home side started the brighter of the two teams and it was Milan who took the lead just before the half hour mark. Robinho’s good work on the right, cutting inside the pitch saw the ball break to Flamini who swept home with his left foot to make it 1-0.
However, it took Napoli just four minutes to level the score, with Goran Pandev poking the ball past Milan keeper Christian Abbiati from close range after a pinpoint pass through by Marek Hamsik.
The equaliser appeared to reinvigorate the visitors who took control of the match as the first half came to a close. An otherwise quiet Edinson Cavani came close to giving his side the lead, but saw Abbiati get his fingertips on a looping effort to maintain parity heading into the break.
Both sides started the second half rather more tentative than they ended the first, with Pandev coming closest to adding a second goal to his name, firing an arrowed strike goalwards for Abbiati to save.
The dynamic of the contest shifted after Flamini’s red card for a rash challenge on Juan Zuniga, with Napoli introducing striker Emmanuele Calaio in attempt to make their numerical advantage tell.
Having been waiting with his strip on since half-time El Shaarawy was finally introduced with less than 20 minutes remaining, but had a limited impact as Napoli dominated possession in their search for a late winner.
However, the Italian international did create a chance for strike-partner Giampaolo Pazzini following some clever juggling inside the opposition penalty area, but Pazzini’s effort sailed high of the target.
The final six minutes of regular time saw four yellow cards dished out by referee Gianluca Rocchi as what had been a free flowing encounter in the first half turned increasingly fiery.
Napoli continued to pepper the Milan box with deep crosses and long-range shots, with Calaio coming closest with a strained header, but Milan held on to a point that keeps them in the hunt for automatic Champions League qualification.