The Parisians exacted revenge on their opponents in the second Le Classique showdown of the season, four months on from a 2-2 draw in the reverse fixture.
That was one of just four occasions this term in which PSG have dropped league points, and they were never at serious risk of doing so again as Kylian Mbappe's strike and Rolando's own goal had them two up inside the opening half-hour.
Edinson Cavani completed the scoring 57 minutes in to lift Unai Emery's charges 14 points clear at the summit, though there was to be a big blow at the end as star man Neymar was stretched off with an apparent ankle injury.
In the first of two meetings between these sides in the space of three days, with a Coupe de France quarter-final to come on Wednesday, PSG made a strong start and were in front 10 minutes in after Mbappe profited from a Jordan Amavi slip.
Mbappe was able to slot the ball home to get the hosts off to a flying start, before Rolando turned Neymar's attempt past Yohann Pele from the next serious attacking move.
Neymar then came close with a curled shot, having sent a header wide at 1-0, but the champions-elect had the third goal they were after 10 minutes into the second half.
Cavani did well to hold off his man and then smash the ball home, giving the home side plenty of breathing space for the remainder of the one-sided affair.
Rolando did come close to pulling one back, forcing a save out of Alphonse Areola with his header, but there was to be no way through for third-placed Marseille.
PSG's night did end on a sour note, however, as Neymar left the field in tears following a challenge with Bouna Sarr, potentially ruling him out of the upcoming Champions League return leg against Real Madrid.
PARIS SAINT-GERMAIN (4-3-3): Areola; Dani Alves, Marquinhos, Thiago Silva, Kurzawa; Lo Celso (Draxler 71'), Diarra (Motta 61'), Rabiot; Mbappe (Di Maria 61'), Cavani, Neymar
MARSEILLE (4-2-3-1): Pele; Sakai (Sarr 59'), Rami, Rolando, Amavi; Zambo, Luiz Gustavo; Thauvin, Payet, Ocampos (Sanson 38'); Germain (N'Jie 73')