Following Marseille’s dramatic exit from the UEFA Champions League in midweek, rumours had been rife that Roberto de Zerbi was going to leave the club.
But after dispelling such talk in his pre-match press conference, Marseille started well and were given a penalty just after the quarter-hour mark, when Moustapha Mbow was penalised for handling in the box.
Mason Greenwood stepped up to roll into the bottom-left corner for his 13th league goal of the season.
Home manager Stephane Gilli’s concerns only grew as Marseille were in total control following the opener.
Subsequently, they came close to doubling their lead midway through the half, when Timothy Weah powered into the Paris box, only for his weak effort to be comfortably gathered by Kevin Trapp.
Ethan Nwaneri - who netted in his first appearance after joining Les Phocéens on loan earlier this month - also came close for the visitors but rifled his shot narrowly wide.
Paris remained below par after half-time, while Marseille picked up where they left off following the restart, and deservedly doubled their lead nine minutes into the second half.
Greenwood flashed the ball across the face of goal to the back post, where Pierre-Emerick Aubameyang was waiting to tap in his sixth of the Ligue 1 campaign.
Such was the one-way traffic that it took until the 82nd minute for Paris to threaten to halve the deficit, but they did so when substitute Jonathan Ikone found himself unmarked in the box to head home.
That set up a classic grandstand finish, which did not fail as Geronimo Rulli was penalised for bringing down Marshall Munetsi in the box, and in the 94th minute Ilan Kebbal stepped up to fire home the resulting penalty kick and complete the turnaround.
The collapse rounds off a disastrous week for De Zerbi, who will be seething at the manner of the points being dropped after Marseille looked to be coasting until the final quarter hour.
Paris fought hard for the draw and now sit seven points above the relegation play-off spot, while Marseille lost ground in the title race and are now seven points adrift of league leaders RC Lens.
Flashscore Man of the Match: Mason Greenwood (Marseille)