Metz scored twice in the final 10 minutes to snatch victory at home to Lyon in Ligue 1.
Alexandre Lacazette struck just after the hour mark for OL when he slammed the ball home from close range following good work from Jordan Ferri.
Kevin Lejeune almost had an equaliser three minutes later, but his effort was well saved. However, the home side scored twice late on to turn the game around.
Yeni Ngbakoto converted from the penalty spot on 82 minutes after Ferri had brought down Bouna Sarr.
Metz then stole it with four minutes remaining when Juan Falcon struck.