In a quickfire start at Roazhon Park, the two sides exchanged early chances within minutes of kick-off, and it was Adi Hutter’s men who claimed first blood when Thilo Kehrer directed Eliesse Ben Seghir’s pinpoint cross into the net with a headed effort.
However, Rennes responded moments later through Ludovic Blas’ third strike of the campaign, which was a thunderous strike from outside the area that left shot-stopper Philipp Kohn helpless between the sticks.
Just as Rennes appeared to be gathering momentum, Monaco swiftly restored their advantage.
Folarin Balogun, showing his poacher’s instinct, latched onto a pass and lobbed over Steve Mandanda midway through the half - that strike meant Les Monegasques have now scored at least two goals in 13 of their last 14 away league games.
With only two wins from their opening six league games, the hosts struggled to recover as half-time approached, leaving Julien Stephan with plenty of thinking to do during the interval.
Ben Seghir, having provided the assist for the opener, almost turned goalscorer a few minutes into the second half when the woodwork denied the Moroccan teenager his moment of glory.
Stephan’s men, though, improved after the break and pressed the visitors as they went in search of an equaliser, but Monaco barely budged in their attempts to record a seventh victory in 10 head-to-head's.
And, despite introducing four fresh faces in the final 20 minutes, Rennes ultimately succumbed to a second league defeat on the trot. It was also their first loss at home in five league outings, while the visitors are now unbeaten in nine games across all competitions this term.
Monaco’s tally of 19 points after seven games is their best start to a campaign, even surpassing the 1960/61 season when they won the French top division for the first time in their history - Hütter will be hoping that proves to be a sign of things to come.
Flashscore Man of the Match: Thilo Kehrer (AS Monaco)