The German defender netted the only goal of the match with just four minutes remaining, tapping in a corner flicked on by Breel Embolo to secure all three points for Monaco, who now have 10 points from their first four group-stage matches.
Despite a tough run in Ligue 1, where they are six points behind leaders Paris Saint-Germain, Monaco are firmly in the hunt for automatic qualification to the Champions League knockout rounds. Kehrer's third goal of the season moved Monaco up to third place, just two points behind leaders Liverpool.
Monaco coach Adi Hutter praised his team’s performance, saying, "The reaction of the team was fantastic. I am very proud of the players, especially since we are one of the youngest teams in the competition. We deserved the win after a strong performance, even if we were a bit lucky with the timing of the goal."
Bologna, in their first Champions League campaign, are struggling. The loss was their third consecutive defeat in the competition, leaving them with just one point and still without a goal, significantly damaging their hopes of progressing to the knockout stage.
Monaco came closest to scoring in the first half when Breel Embolo’s effort was saved brilliantly by Bologna goalkeeper Lukasz Skorupski, who tipped the Swiss striker’s shot onto the post. A Wilfried Singo goal was ruled out for a foul on Skorupski after a VAR review.
Bologna pressed in the second half, but Kehrer’s late strike left them with little chance of a comeback, securing a vital win for Monaco.