Thongchai Jaidee of Thailand took a one-stroke lead at the Wales Open after shooting a 4-under par 67 in the third round at Celtic Manor on Saturday.
Tied for second were Joost Luiten of the Netherlands, who had the low round of the day with a 64, and overnight leader Ross Fisher of England (71).
Lee Slattery, who was in second place overnight, found water twice on the par-3 third on his way to a 76.
Italy's Matteo Manassero could face a fine from the European Tour after throwing his ball away and slamming his putter to the ground after missing a 3-foot putt for par at 17.
The 19-year-old Manassero, who qualified for the U.S Open on Monday, apologized after his round of 68.
"It is bad, I totally understand it is a bad thing to do," Manassero said. "Sometimes, when there is tension and adrenaline it is difficult to control. But it is a bad attitude and it shouldn't have been done."
Ryder Cup hopeful Paul Lawrie shot a 71, tied for 26th.