Gonzalo Higuain headed a dramatic late winner as Juventus pulled off a sensational turnaround to beat 10-man rivals Inter 3-2 in the Derby d'Italia, moving the Serie A leaders four points clear of Scudetto rivals Napoli.
Defending champions Juventus looked set to open the door for Napoli - who won 1-0 in Turin last weekend to breathe new life into the title battle - after Inter came from behind at San Siro on Saturday.
Matias Vecino's 18th-minute red card, after Douglas Costa had rifled Juve in front, appeared likely to ensure Massimiliano Allegri's men would comfortably claim three points.
However, Juve collapsed after the break, Mauro Icardi heading Inter level before an own goal from Andrea Barzagli put the hosts in front.
Much more drama was still to come, though, with Juan Cuadrado's cross deflecting in off Milan Skiriniar in the 87th minute prior to remarkable scenes in the closing stages.
Higuain had been guilty of missing a fantastic chance with the score at 1-1, but the former Napoli striker significantly dented the Partenopei's title hopes with an 89th-minute header to spark wild celebrations and ensure the Scudetto, somewhat improbably, remains in Juve's hands.
Napoli must now respond when they head to Fiorentina on Sunday, while Inter remain outside the Champions League places and could yet lose further ground to fourth-placed Lazio.
