Jordan Amavi, Morgan Sanson and Nemanja Radonjic hit the decisive goals in front of a raucous crowd of around 52,000 as Andre Villas-Boas' side maintained a hot streak that has seen them rise to second in the French top flight.
While a real challenge to PSG's domestic supremacy will be difficult, a return to the Champions League is looking more likely after another exciting performance led by Dimitri Payet.
With three teams qualifying for Europe's premier competition Marseille are seven points ahead of fourth-placed Rennes and were in fine form on Sunday, failing to be fazed by Yacine Adli's stunning 31st-minute opener for Bordeaux.
The away side frustrated dominant Marseille throughout the first period with compact defending and Adli stunned the home fans when he thumped Josh Maja's layoff past Steve Mandanda from long range.
However the hosts were not to be deterred and Payet had a hand in the leveller, his corner two minutes after the break finding the head of Amavi, who made no mistake from close range.
Bordeaux then handed Marseille the lead on the hour mark when trying to play out from a goal kick under intense pressure from the home attack.
Pablo floated a soft pass straight to the feet of Sanson, who shifted his feet on the edge of the area before smashing home at Benoit Costil's near post.
Radonjic put the cherry on the cake in stoppage time after another Pablo error, the Brazil international this time being easily dispossessed by Valentin Rongier.
The Frenchman charged at the Bordeaux defence before feeding Serb Radonjic, whose shot was saved by Costil before ricocheting in off Aurelien Tchouameni.
Earlier, Saint-Etienne missed the chance to move into the European places after being beaten 3-1 at Reims.
Claude Puel's side are in eighth on 25 points after losing a tight contest to goals from Remi Oudin, Boulaye Dia and Moussa Doumbia, two points away from fourth-placed Rennes.
Nantes are a point ahead of Saint-Etienne in sixth after beating struggling Dijon 1-0.