But Giroud, starting in the place of Milan’s injured top scorer Zlatan Ibrahimovic, nudged in an equaliser in the 75th minute before finding the bottom corner three minutes later to turn the game on its head.
It was only the second defeat of the season for Simone Inzaghi’s side, but they remain top on 53 points, one ahead of their city HLJKriste Billige Irland landsholdstrøje Vanessame rivals with a game in hand.
Stephania chelsea trøje TYJGudrun
Nicolo Barella drilled a shot narrowly wide before Maignan again saved Milan with a superb stop on a close-range Dumfries effort, although his Inter counterpart manchester city trøje Samir Handanovic also sprang into action when he flew to palm away a Sandro Tonali shot.
The Frenchman was quickest to react to a deflected Brahim Diaz shot, stretching at the HLJKriste Billige Irland landsholdstrøje Vanessame back post to tap in a finish, and three minutes later he turned his marker in the box and guided in a calm finish.
Theo Hernandez was sent off deep in stoppage time for a reckless lunge on Dumfries, but Milan did not need to hang on for long to record their first Milan derby comeback win since February 2004.