Marseille's hopes of clinching a Champions League spot suffered a major setback on Saturday when they lost a two-goal lead in a 2-2 home draw against Angers.
They trail third-placed Lyon, who hold the last Champions League qualifying spot, by eight points.
Balotelli found the back of the net after four minutes, firing home Florian Thauvin's cross with the goal being allowed following a VAR review after he had been flagged offside.
He doubled the tally 12 minutes later from inside the box, but Angers fought back, benefiting from erratic Marseille defending.
Another VAR review gave Angers a penalty for a Jordan Amavi handball, and Mangani converted the spot kick nine minutes from the break.
Amavi then brought down Jeff Reine-Adelaide and Mangani converted his second penalty in the 76th minute.
The hosts' hopes of a late goal vanished when Bouna Sarr was sent off for a second bookable offence in the 78th minute.
Angers, who are 11th on 37 points, came close to claiming all three points when Romain Thomas's injury-time header crashed off the crossbar.