Folarin Balogun's first Champions League goal proved enough to earn Monaco their first win of this season's league phase against 10-man Bodo/Glimt.
Having recorded impressive draws against Manchester City and Tottenham on matchdays two and three, the French side began with confidence, dominating possession but struggling to break through the rigid home defence.
Former Liverpool forward Takumi Minamino had the best of the early chances, but his long-range effort was blocked on the edge of the box before Mohammed Salisu's last-ditch block kept out Bodo skipper Patrick Berg's goalbound volley.
With the sides set to go into the interval at a stalemate, Balogun produced a rare moment of quality to break the deadlock.
The United States international made a forward dart to reach Maghnes Akliouche's through-ball before switching the ball on to his left foot and firing high inside the near post beyond keeper Nikita Haikin.
Bodo stepped up after the break in a bid to extend their nine-game unbeaten run in all competitions, but their efforts proved fruitless.
Jens Petter Hauge's curling free-kick was denied by a sprawling Philipp Kohn save, before Kasper Høgh fired another golden chance wide of the far post.
With time fast running out and things getting desperate for the home side, substitute Jostein Gundersen was sent off.
After initially receiving a yellow card for a rash sliding tackle from behind, a lengthy video assistant referee (VAR) check resulted in the call being upgraded to a straight red.
It ended the home side's hopes of claiming anything from a hard-fought encounter and they remain winless after four games.
On Matchday five Bodo/Glimt welcome Italian giants Juventus to Aspmyra on Tuesday, 25 November (20:00 GMT), while Monaco head to Cyprus to take on Pafos FC on Wednesday, 26 November (17:45 GMT).
Player of the match
After the opportunity to rate players has closed, the score displayed represents the average from all the submissions by BBC Sport users.
