Caen captain Julien Feret had the game's first chance on six minutes as he charged forward after collecting from Jean-Victor Makengo, but his tame effort was straight into the hands of Steve Mandanda in the Marseille goal.
It was the visitors who bagged the opener just before the quarter-hour mark when Michy Batshuayi grabbed his 12th of the season.
Abdel Barrada was provider, collecting a cross from the left and working hard to keep possession before passing to the Belgian to poke past the line.
Batshuayi could have doubled his tally at the half-hour mark after Bouna Sarr pounced on a loose ball and crossed into the box, but he could only drag his effort wide.
Caen had a chance to restore parity minutes later when Bazile set up Feret with a perfect cross, but the Frenchman mistimed his shot and sent the ball wide.
The contest remained an even affair until the hour mark when Batshuayi set up his side's second, unselfishly passing to Georges-Kevin Nkoudou in the left of the box for his fourth of the season.
Ronny Rodelin provided the hosts with a way back into the game on 67 minutes, however, meeting Feret's free kick from the edge of a box with a run and jump to head past Mandanda.
The match looked to be heading for a nervy finish but Sarr put the result beyond doubt seven minutes from time, collecting from substitute Jacques-Alaixys Romao on the left to leave Remy Vercoutre with no chance.
The result moves Marseille up to seventh in the league, one point behind sixth-placed Caen, who have now suffered three defeats in a row.