Ousmane Dembele and Kylian Mbappe both scored twice as Paris St-Germain moved one step closer to the Ligue 1 title.
PSG will win their third consecutive title if Monaco fail to beat Lille later on Wednesday [20:00 BST].
Dembele opened the scoring and Mbappe netted with a clever flick.
Mbappe found Dembele for his second of the game, producing sublime skill by nutmegging Nathaniel Adjei and crossing into the box before doubling his own tally in stoppage time.
The France captain’s strikes made him the first French player to reach the 25-goal mark in four consecutive seasons in one of Europe’s top five leagues.
Lorient’s consolation came as Bamba Dieng headed in Benjamin Mendy’s pinpoint cross midway through the second half.