Lorient moved up from 18th to 16th following their 5-1 home demolition of 15th-placed Metz.
Bernard Casoni's side ran riot after the break, having gone in at half-time level at 1-1 after their opener from Michael Ciani was cancelled out by a Cheick Diabate penalty.
Majeed Waris restored Lorient's advantage soon after the interval, and a quickfire Jimmy Cabot brace and Benjamin Moukandjo strike followed.