David Howell of England shot a 4-under 67 to share the lead with Denmark's Anders Hansen at 6-under after the third round of the French Open on Saturday.
South African George Coetzee sits one shot behind the co-leaders after his 1-under 70. But overnight leader Marcel Siem of Germany had a torrid time, managing only a 2-over 73 to fall two behind the leaders.
Howell, out in a two-under 34, added further birdies on the 14th and short 16th on his way back to the clubhouse just before a thunderstorm halted play.
''It was a great round,'' said Howell, who had five birdies overall. ''I had a nice bit of luck at the last (hole). The seven-iron was my one really poor shot, but it went my way today and it scrambled over the water.''
Hansen and Coetzee both started strongly, but Hansen bogeyed the 16th and 17th and Coetzee bogeyed the 16th and 18th.
Siem missed an easy birdie chance on hole nine, meanwhile, shaking his head ruefully as he realized his lead was slipping away. He finished the day with four bogeys and two birdies.
Frenchman Raphael Jacquelin moved level with Siem at 4-under overall heading into Sunday's final round. Sweden's Henrik Stenson and Ian Poulter of England are both a stroke behind them and also in contention.
Lee Westwood got injured before play - interrupted by a thunderstorm for the second straight day - even started.
Westwood strained his right groin muscle when he slipped up walking to the first tee. He looked in pain and double-bogeyed the opening hole and bogeyed the next five.
But Westwood's form improved with two birdies on the back nine and he finished with a 5-over 76.