Marseille were in complete control during the opening half-hour, during which the best chance came for Adrien Rabiot, who fired towards the roof of the net from just inside the penalty area, but Brice Samba made a smart save.
However, the hosts were handed a golden opportunity to take the lead after being awarded a penalty with just over half an hour played, when Michael Murillo was ruled to have handled the ball in the penalty area following a VAR review.
Arnaud Kalimuendo was the man who stepped up to take the spot-kick, but his strike towards the bottom-left corner was saved emphatically by Geronimo Rulli.
Kalimuendo did manage to make up for it just before the break though, as the Frenchman latched onto a pass from Lorenz Assignon, before firing into the bottom-left corner.
Yet, Marseille showed why they had kicked off having won seven of their previous eight league games on the road, and Roberto De Zerbi’s side equalised just two minutes later through Mason Greenwood.
The Englishman was found by Murillo, before he fired a right-footed strike into the bottom-left corner.
The away side managed to fashion more chances at the start of the second half too, and managed to take the lead four minutes after the restart.
The goal came courtesy of Rabiot, as the midfielder rose highest to head Greenwood’s cross into the top-right corner. Far from try to hold onto what they had, Marseille continued to attack the Rennes defence after taking the lead.
With Rennes flagging somewhat, Marseille went close to extending their lead through Luis Henrique, after the Brazilian worked his way into the box before drilling a strike towards the bottom-right corner, but Samba pulled off an astonishing save to thwart him.
Murillo went close for the visitors just moments later too as he tried to prod the ball home from the edge of the six-yard box but Samba managed to make the save again.
The last 20 minutes of the game saw very little in the way of goalmouth action, and the game ended with Marseille taking all three points.
The result means De Zerbi’s side remain in second place, four points behind Paris Saint-Germain, having now played a game more.
Meanwhile, Rennes continue to languish just above the danger zone, with just one point separating them from Saint-Etienne in the relegation play-off spot.
Flashscore Man of the Match: Mason Greenwood (Marseille)