Ibra on target as Milan brush aside Brescia
The Rossoneri, chasing a first scudetto since 2004, moved three points clear at the top having been briefly caught on Friday by Lazio who beat troubled champions Inter Milan 3-1.
Sixth-placed Inter are now 10 points behind city rivals Milan and their chances of a sixth straight title look remote after 15 games of the season.
Milan, who drew 1-1 with Sampdoria last weekend in a rare blip, took no time at all in dismantling promoted Brescia.
Midfielder Kevin Prince Boateng netted his first league goal for the club in the fourth minute after Ibrahimovic's assist.
Forward Robinho, preferred to fellow Brazilian Ronaldinho for a seventh straight game, extended the lead after 28 minutes when he intercepted a backpass before Ibrahimovic produced great individual skill to make it three on the half hour.
The giant Sweden striker, who failed to net against Samp, scored his eighth of the league campaign and no Milan fan would doubt that the addition of the ex-Inter and Barcelona man is the key reason why they are top of the table.
The shrewd coaching of new boss Massimiliano Allegri, whose only previous Serie A experience was with perennial mid-table team Cagliari, has also made a difference.
The softly-spoken manager has shown his tougher side by daring to leave the underperforming Ronaldinho out despite the playmaker being club owner Silvio Berlusconi's favourite.
The result, along with limiting Andrea Pirlo's slowing influence on the side, has been a quicker and more incisive Milan than the versions seen in the last five years.
"It's important to carry on like this, often it's happened and it will happen that someone is left out. The key thing is that those who play give their all," Allegri told Sky.
"Tonight we can be happy but the championship is still long. Last season (runners-up) Roma made up 14 points on Inter."
Ronaldinho came on in the second half but, despite long-term injuries to Alexandre Pato and Filippo Inzaghi, the former world player of the year is just a spare part these days and local media say he may leave in January as Milan seek another striker.
In the early game, seventh-placed AS Roma threw away a two-goal lead to draw 2-2 at Chievo and could easily have lost.
Davide Moscardelli sparked Chievo's comeback midway through the second half before Pablo Granoche equalised seven minutes from time and Roma's Daniele De Rossi was sent off for a foul.
Adriano, who criticised Roma coach Claudio Ranieri in midweek for not giving him enough playing time, finally got a start and was involved in both first-half goals for Brazilian compatriot Simplicio on a terrible pitch.
Ranieri rested forwards Marco Borriello and Francesco Totti after last weekend's 3-1 defeat at Palermo and with one eye on next week's crucial Champions League group match at CFR Cluj.
Next weekend's games are threatened by a players' strike.