Benjamin Hebert surged into a three-shot lead after what he called a "crazy" third round at the China Open, as overnight leader Wu Ashun had a day to forget.
Frenchman Hebert recorded an eight-under 64 – the best score of the event so far – on day three in Shenzhen, with seven birdies, an eagle and a solitary bogey.
He had an amazing back nine to thank for his advantage, having been level par at the turn before going eight under over the last nine holes to end Saturday's round at Genzon Golf Club on 17 under for the tournament.
Hebert, who is seeking a maiden European Tour title, said: "Crazy game, isn't it? I played very badly on the front nine where I didn't feel good in my swing.
"I just tried to keep focused on what I'm doing and I found my rhythm in the back nine so I'm happy. It's my first time leading after 54 holes and we'll see what happens."
Mikko Korhonen and Jorge Campillo, who claimed his maiden European Tour title with a Trophee Hassan II triumph last weekend, are in a tie for second place at 14 under.
Home favourite Wu struggled with a level-par 72 that dropped him to fourth, a run of four straight bogeys from the 12th to 15th holes costing him.
He sits four off the lead, with Hebert's compatriot Victor Dubuisson a further shot back at 12 under par.
Chinese amateur Yang Kuang, the 14-year-old who on Friday became the second youngest player to make the cut at a European Tour event, had his best day yet, shooting a three-under 69 to continue a remarkable week.
The final round will start early due to the threat of storms.