(CNN) - AC Milan took a giant step to delight the Italian Serie a title off Internazionale after Alexandre Pato scored twice in Saturday victory derby 3-0 at San Siro, which ended with both teams reduced to 10 men.
Inter rule stretches back for the season 2005-06, but the Nerazzurri placed second - coached by former boss of Milan Leonardo - now trail the Rossoneri five points with seven games to play.
Zlatan Ibrahimovic scored the winner against his former team when Milan defeated Inter in November, but its suspension meant that Pato led the attack with fellow Brazilian Robinho.
And the young man of 21 years gave Milan - whose last Crown league came in 2004 - the lead after just 44 seconds.
He played a one-two with Gennaro Gattuso on the edge of the Inter area, but return attempt of the veteran community pass entered the path of the onrushing Robinho and Pato pouring on the loose ball to beat goalkeeper of his fellow countryman Julio Cesar.
Cesar was beaten almost once more than seven minutes before the half, but shot deflected Mark van Bommel loop on the top bar and security.
Inter should have equalized two minutes before the break, but top scorer Samuel Eto'o ' o made an unusual miss that he scuffed his shot wide objective.
Hopes for his team to win parity suffered a blow huge nine minutes after the interval when the last man Christian Chivu was expelled for nailing Pato heels as the push forward towards the goal of Cesar.
Pato, playing in his first derby in Milan, doubled the score in the 62nd minute when he headed the House of mishit Ignazio Abate shot after the right rear was put into space by Clarence Seedorf.
Milan had the ball in the net for the third time in the 76th minute, but it is second-half substitute Mathieu Flamini - which replaced the Gattuso - was clearly far remain.
But another goal was inevitable, with replacement Antonio Cassano scoring from the penalty spot after he was dragged down by Javier Zanetti - his third since joining the Sampdoria in the January transfer window.
But the former Italy before a ruined his own night by get booked twice in a minute - timed the first to take his shirt to celebrate his goal and the second for a bad tackle on substitute Ivan Cordoba.
The result means that inter will lose second spot if Napoli win at home to placed in fifth Lazio Sunday.
Inter still take advantage of 64-60, in 176 meetings between the rivals but must now retrieve opening home leg of the quarter-final of the League of Champions against the German club Schalke on Tuesday.
In Saturday last another match, Brescia is the area of relegation on the difference of goals over Cesena with a victory of 3-1 at home at the 10th Bologna.