Rennes scored twice in the last five minutes to secure a 3-2 win against Marseille to leave the former giants just two points off the bottom of Ligue 1.
The home side dominated most of the ball in the early exchanges but both sides had little to shout about as shots at goal proved hard to come by.
Yoann Gourcuff went closest for the hosts, but his free-kick cleared Yohann Pele's top corner before Florian Thauvin had a similar effort at the other end when his set-piece also failed to find the target.
Then, with less than five minutes until the interval, the game sprung into life as Rennes struck first in superb style.
An error from Marseille defender Tomas Hubocan gifted Giovanni Sio possession and, with Pele off his line, the Ivorian lifted the ball over the stranded goalkeeper to open the scoring.
Their lead lasted just a matter of minutes, though, when Benjamin Andre felled Thauvin inside the penalty area before Bafetimbi Gomis confidently slotted home the resulting penalty for his third Marseille goal of the season.
In what proved to be a blistering start to the second half, Paul-Georges Ntep was millimetres away from reclaiming the hosts' lead when his effort came back off a post.
Then, with 50 minutes on the clock, Marseille turned the game on its head when Clinton Njie opened up the Rennes defence before teeing-up Gomis to slot home his second goal of the game.
Marseille had to see out the last 25 minutes with 10 men when Zinedine Machach was shown two yellow cards in the space of 10 minutes.
And that gave Rennes the advantage they needed to dramatically turn the game on its head.
Kamil Grosicki scored from the penalty spot with five minutes remaining after Hubocan fouled Ludovic Baal in the area.
Then, with two minutes left on the clock, Adrien Hunou headed Grosicki's delivery beyond Pele to break Marseille hearts in dramatic fashion.