Late equalizer snatches Monaco draw
Monaco slipped to five points behind PSG, which beat Bordeaux 2-0 on Friday.
Vincent Aboubakar headed Lorient in front in the 12th minute following good work by Kevin Monnet-Paquet down the right flank.
Monaco leveled three minutes from halftime when Valere Germain's weak shot beat Lorient goalkeeper Florent Chaigneau.
Lorient almost restored its lead immediately after the break but Bruno Ecuele Manga's effort was cleared off the line by Andrea Raggi.
The home side did go in front in the 73rd. Danijel Subasic's clearance fell to Aboubakar, who found Jeremie Aliadiere for a tap in.
Substitute Layvin Kurzawa rescued a point for Monaco with a low strike three minutes from time.