Inter 0, Milan 1
Milan returned to the top of Serie A tonight with victory over city rivals Inter in the 275th Derby della Madonnina at the San Siro.
A penalty from former Inter striker Zlatan Ibrahimovic in the fifth minute was enough to decide a game which Milan ended with 10 men after Ignazio Abate was sent off on the hour mark.
The result takes Milan back to the top of the table above Lazio and leaves Inter six points adrift in fifth.
The eagerly-anticipated derby started with a bang as Milan were awarded a penalty after just four minutes.
Marco Materazzi caught Ibrahimovic as he pulled the ball back just inside the area and there were no complaints from the Nerazzurri defender when the spot-kick was awarded.
Ibrahimovic stepped up to blast the penalty past Luca Castellazzi, who was again deputising for the injured Julio Cesar in the Inter goal.
Milan, officially the visiting team at the San Siro, did not want to settle down having taken an early lead and they continued to trouble the hosts' defence.
Ibrahimovic broke the offside trap in the 13th minute and sent the ball towards Mathieu Flamini in the centre, where Ivan Cordoba made a despairing lunge to clear the ball ahead of the Frenchman.
Ibrahimovic was left in acres of room again in the penalty area when he lifted the ball over Lucio and again looked for a team-mate in the centre, but Materazzi this time made the clearance just ahead of Clarence Seedorf.
A volley from the inspired Swede only just cleared the top of the crossbar as Inter did not know what was hitting them.
An injury to Joel Obi turned out to be a blessing in disguise for the home team as coach Rafael Benitez was forced to change his side and give it a more attack-minded look with Coutinho coming on.
The Nerazzurri finally found a foothold in the game and Wesley Sneijder sent a free-kick just inches wide of the post into the side-netting after being fouled by Gennaro Gattuso, who was riding his luck having already been booked.
Another Sneijder free-kick in the 56th minute tested Christian Abbiati, who pushed the ball away.
Abate tried to be a hero for Milan when he tried to play on despite being carried off on a stretcher with a back injury, but he turned into a villain when he was shown a second yellow card for a clash with Goran Pandev when Luca Antonini was already stripped and ready to replace him.
Antonini came on anyway to replace Robinho as Milan set their stall out to defend their lead for the final 30 minutes.
Inter, try as they might, simply could not find a way through the massed ranks of red and black shirts and the defending champions had to admit defeat as their city rivals held on for the win.