The home supporters spent the opening 15 minutes in silence, in protest at how their club is being run – though they had little to cheer early on in any case.
Instead, Galatasaray’s vociferous travelling fans should have been celebrating 13 minutes in, but Ilkay Gündoǧan inexplicably blazed over from eight yards out.
Monaco finally threatened midway through the half, with Maghnes Akliouche forcing Uğurcan Çakir to parry behind, before Balogun headed over from the resulting corner.
Akliouche drew another save from Çakir on the half-hour mark, before Leroy Sané had the visitors’ first effort on target four minutes later when he shot straight at goalkeeper Lukas Hradecky after jinking through the home defence.
Galatasaray’s Victor Osimhen also looked dangerous throughout the half, as the striker sought to extend a run of scoring in eight successive major European games, having netted a dozen in that time.
Takumi Minamino’s past three goals for Monaco had all been match openers, and he almost added another three minutes after half time, but his volley was too close to Çakir.
The Japan international could have played a vital role in changing the scoreline shortly after, though, when he was bundled over by Davinson Sánchez as he looked to convert the rebound.
After a VAR check, referee Danny Makkelie gave a penalty, but captain Denis Zakaria’s spot-kick down the middle was saved by Çakir’s outstretched leg.
The goalkeeper was forced off through injury just beyond the hour mark, with Günay Güvenç replacing him, and Monaco capitalised on the disruption almost immediately.
Galatasaray failed to clear a 68th-minute corner, and Balogun pounced in the six-yard box for his seventh goal of the season across all competitions, making him the French club’s top scorer.
With that strike being only Monaco’s fourth goal in six home matches, there was always a feeling that they would need to make it count.
However, they continued to press forward and Lamine Camara should have sealed victory 10 minutes from time when he side-footed over from 15 yards.
The win puts Monaco on nine points – and behind Galatasaray only on goal difference – with two rounds of the UCL league phase to play, though both teams seemingly remain well-placed to make the knockout round play-offs.
Flashscore Man of the Match: Folarin Balogun (AS Monaco)
