Manuel Locatelli's stunning strike earned AC Milan a 1-0 victory over Serie A leaders Juventus, who controversially had a Miralem Pjanic goal ruled out at San Siro.
Teenage midfielder Locatelli fired a sensational effort beyond Juve goalkeeper Gianluigi Buffon in the 65th minute, with Vincenzo Montella's side consequently moving to within two points of their table-topping opponents on his 200th Serie A match as a head coach.
After losing Paulo Dybala to injury, the midfielder's 35-yard free-kick flew beyond the outstretched leg of Leonardo Bonucci, who raced in from a legal position, to nestle in the back of the net.
The goal initially stood, but referee Nicola Rizzoli consulted with his assistants following protests by the Milan players and pulled play back for Benatia's infringement, despite him not appearing to have interfered with play.
It was a bitter defeat for Massimiliano Allegri's side, whose only prior loss this term came in the same stadium when they were beaten 2-1 by Inter.
It took Juve less than a minute to test Gianluigi Donnarumma, but Dybala's attempt to guide Alex Sandro's cross inside the near post was held by the goalkeeper.
Their positive impetus soon subsided, though, with Milan punishing them midway through the second half. Locatelli collected Suso's pass and took one touch on the right-hand side of the box before rifling a shot across Buffon and in off the bar.
Allegri's team were unable to create any clear opportunities as they attempted to restore parity, with Higuain receiving minimal service in a laboured performance in front of goal.
But Donnarumma did have to produce a stunning save to keep a 25-yard strike from Sami Khedira out of the top corner in the fifth minute of stoppage time, as Juve finally registered their first shot on target of the second half.
That meant Milan's brilliant start to the campaign continued with a first top-flight win over Juve since November 2012 - ending a run of seven consecutive top-flight defeats in the fixture.
