MILAN (REUTERS) - Substitute Arkadiusz Milik rescued a dramatic 2-2 draw for Napoli following a topsy-turvy second half at Sassuolo which saw the visitors lead 1-0, gift an equaliser, and then hit the woodwork twice on Sunday.

The draw kept third-placed Napoli one point behind AS Roma, who visit basement club Pescara on Monday, and nine behind leaders Juventus, who play later on Sunday at home to Genoa.

Dries Mertens headed Napoli in front from Jose Callejon's cross in the 52nd minute to delight of the visiting fans behind the goal.

But a mistake by Napoli's usually inspirational captain Marek Hamsik allowed Sassuolo to level seven minutes later when Domenico Berardi intercepted the Slovakian's headed back pass and fired past Pepe Reina.

Mertens smacked a free kick against the crossbar, and Lorenzo Insigne hit the inside of the post before Sassuolo sneaked a second in the 80th minute, Luca Mazzitelli firing home after Napoli failed to clear the ball.

Milik was brought on and equalised within three minutes when he hooked the ball in from close range with Sassuolo claiming offside as Napoli extended their unbeaten league run to seven games.