Thongchai Jaidee of Thailand posted a 3-under round of 68 on Saturday to move 8-under and take a two-shot lead heading into the final round of the French Open.
Northern Irishman Rory McIlroy and South Korea's Wang Jeung-hun posted 1-under 70s, having been level with Jaidee and two other players overnight.
Jaidee played consistently with three birdies, but McIlroy's third round was erratic. The four-time major winner had six birdies, three bogeys and one double-bogey.
Wang's round featured three bogeys and four birdies.
Defending champion Bernd Wiesberger of Austria posted 70 and is one shot behind at 5-under, followed by South African Brandon Stone and four other players at 3-under.
Stone shared the overnight lead, but fell away with a 2-over 73 — including double bogey on the 18th hole.