Thiago Silva opened the scoring before Ezequiel Lavezzi and Edison Cavani added goals. Zlatan Ibrahimovich then scored twice in the final six minutes to put in a convincing display from the reigning French champions.
Elsewhere in France this weekend, Bordeaux beat Lille 1-0. The win propelled Bordeaux to sixth place whil Lille has been overtaken by Monaco, now in second place, who beat AC Ajaccio 1-0.
Struggling Lyon meanwhile beat Bastia 3-1 to rise to tenth place.