Inter Milan moved top of Serie A as a goal from Fredy Guarin earned a narrow derby victory over AC Milan.
Roberto Mancini’s side maintained their 100% start by continuing their impressive recent record against their city rivals at the San Siro.
Colombian midfielder Guarin found the bottom corner from outside the area in the 58th minute.
Substitute Mario Balotelli hit the post on his first appearance since rejoining on loan from Liverpool.
The 25-year-old former Inter striker was immediately into the action, taking responsibility for set-pieces, striking the frame of the goal from outside the box and forcing a fine save from Samir Handanovic.
Equally as importantly in his attempts to atone for an abject 12 months at Anfield, the Italy international refused to respond to Inter’s attempts to provoke him during an encouraging cameo.
By doing so, he seemed to acknowledge that mental strength as much as anything else will play a major role in his bid to prove that he can still be success on the big stage.
Are Inter serious title challengers?
Juventus have won the last four Serie A titles, but their shaky start to the season – one point from their opening three matches – could open the door to a title bid from another team this season.
And Inter could be that side, having made their best start to a season for 13 years, returning to the summit of Serie A after the latest victory.
It was another display which posed almost as many questions as it answered, as they were forced to defend for lengthy periods.
But it is now just one defeat in nine games against their fierce rivals, and further evidence of their ability to grind out wins when not playing to their maximum.