Inter Milan are unbeaten in 17 Serie A games
Inter defender Stefan de Vrij scored a stoppage-time equaliser to deny AC Milan victory in Serie A.
Sergio Conceicao's side looked set to complete the league double over rivals Inter in the Derby della Madonnina when Tijjani Reijnders put them ahead just before the break.
The Dutchman reacted quickest to rifle a finish into the roof of the net after visiting keeper Yann Sommer had parried Rafael Leao's angled shot.
But in a tense finale, Inter levelled when Nicola Zalewski chested the ball into the path of defender de Vrij who hooked the ball into the net from close range.
The result left Inter two points behind leaders Napoli, while Milan remain eighth and five points off the Champions League places.
Inter had been unlucky with Denzel Dumfries one of three players denied by the woodwork, while AC Milan keeper Mike Maignan also slid out and smothered Dumfries' fierce strike.
Former Manchester City captain Kyle Walker made his AC Milan debut, with England manager Thomas Tuchel watching in the stands.
