The uninspired hosts dominated possession but never really threatened OM goalkeeper Steve Mandanda, waiting more than an hour to record their first attempt on target.
The visitors had their chances in the first half but striker Andre-Pierre Gignac lacked a cutting edge.
Lyon stayed second with 53 points from 28 games, four behind PSG who defeated bottom club Nancy on Saturday thanks to Zlatan Ibrahimovic's 23rd and 24th league goals.
Marseille occupy the third and final Champions League qualifying berth on 50, two more than fourth-placed St Etienne and fifth-ranked Nice, who beat Montpellier 2-0 on Sunday thanks to the promising Stephane Bahoken's first two goals in Ligue 1.
Champions Montpellier are seventh on 44.