Looking to arrest their recent slump, the visitors got off to the perfect start as they struck first, albeit against the run of play on eight minutes.
A through ball from Arnaud Nordin appeared to be overhit, but Esteban Lepaul showed fantastic poaching instincts to slide and divert the ball past Robin Risser into the far corner.
Odsonne Edouard was the most potent attacking threat for Lens and came closest to finding a leveller midway through the half, but his shot sizzled just wide of the post with Mathys Silistrie well beaten.
Edouard’s persistence was rewarded just before half-time, as he fired the home side level on 41 minutes.
A long ball from Aguilar appeared hopeful, but the striker demonstrated his strength to hold off his marker before calmly tucking the ball into the back of the net.
Despite dominating the first half, the home side found themselves on the back foot after the restart, and only a magnificent last-ditch tackle from Malang Sarr denied Lepaul the chance to grab his second goal as he prepared to shoot in the box.
That proved to be a vital moment in the game, as minutes later, Lens completed the comeback when Aguilar headed home from close range after a pinpoint cross from Florian Thauvin.
Aguilar’s joy was short-lived, however, as less than a minute later, he was shown a second yellow card, leaving the home side to play with 10-men for over half an hour.
Rennes responded with four changes in an attempt to take advantage, but they were caught out at the other end on 78 minutes when Allan Saint-Maximin’s powerful shot went through Silistrie’s hands.
The result sees Lens return to the top of Ligue 1 for now, although Paris Saint-Germain are only one point behind with a game in hand. Rennes are still in sixth but are now winless in four league games, and could drop to eighth depending on other results this weekend.
Flashscore Man of the Match: Odsonne Edouard (RC Lens)