The attacking midfielder scored in the last minute under the eyes of the onlooking Argentine, who has been in talks to take over the reins at the Stade Velodrome
The former Chile boss watched live at Stade de la Mosson as OM’s push for Europe continued, with Mathieu Valbuena and Andre-Pierre Gignac twice giving the Provence side the edge.
But the hosts showed resolve and battled back thanks to strikes from Remy Cabella and substitute Morgan Sanson, before Dimitri Payet scored a fortunate winner with only a minute remaining.
Marseille did much of the early pressing and were rewarded on the stroke of half-time when Valbuena looped a tremendous lob over Geoffrey Jourdren, who had earlier denied Gignac with a fine reflex block.
But the fragility of the visitors was on show as Cabella pounced on a rebound early in the second half to level matters.
This was a rare blip from OM, who promptly fought back and moved into the lead when Brice Dja Djedje’s low cross from the right picked out Gignac at the back post. A thumping shot from the former Toulouse man was enough to beat Jourdren.
Once more Marseille lacked killer instinct. Again Cabella did the damage, but after his low shot was parried by Mandanda, Sanson reacted quickest to score.
Perhaps for the first time, Montpellier exerted a spell of concerted pressure upon their opponents, with Hilton heading narrowly over and M'Baye Niang allowing a glaring chance to slip wide.
Within moments of the on-loan AC Milan striker missing, Payet cut inside from the left flank to shoot. His effort took a heavy deflection that looped the ball over the helpless Jourdren with seconds remaining.
While this win keeps Marseille in sight of a European spot, the club will be arguably more heartened by the news from the stands, where Bielsa told RMC that he is “optimistic” a deal can be concluded with the Stade Velodrome club that would likely see him take over as head coach next season.
A decision is expected from the former Chile boss in the next week.