Before the international break, Milan had secured their first league victory under manager Massimiliano Allegri's second tenure, beating Lecce 2-0. They looked to build on that momentum in front of their home fans.
Both teams started strongly, with Santiago Giménez forcing a save from Lukasz Skorupski early on. Bologna thought they had taken the lead through Nicolo Cambiaghi, but his goal was ruled out due to an offside position.
The visitors continued to threaten, with Riccardo Orsolini and Pervis Estupinan both creating chances. However, the game slowed down in the latter stages of the first half.
After the restart, Milan gained more control and looked more likely to score. They eventually broke the deadlock around the hour mark through Luka Modric, who scored his first goal for the club since joining from Real Madrid in the summer.
Modric, despite turning 40, continues to play at a high level, and his goal sealed the win for Milan. The team looked to put the game to bed, but Bologna rarely threatened the opposition's goal.
Even after going behind, the Rossoblu struggled to create clear chances, with Pietro Terracciano, a second-half substitute for the injured Mike Maignan, making a few crucial saves.
AC Milan's win means they have now overseen two victories in the opening three matchdays of a Serie A season for the first time in five overall campaigns under Massimiliano Allegri.
Bologna, on the other hand, have now lost five of their past six league matches and have scored just once so far this term. Vincenzo Italiano will be looking to improve his team's performance in the coming weeks.
's Man of the Match award went to Luka Modric for his crucial goal and his overall performance in the game.
For more information and statistics from the match, check out 's match centre.