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 and overnight leader Ross Fisher of England.
Thongchai, who holed seven birdie putts, has won four times on the European Tour but has yet to win in mainland Europe.
''The weather in Europe is very difficult for me,'' Thongchai said. ''I've learnt a lot about how to work in these conditions though and it would be important to me to win here.
''I went out there with a very good game plan, knowing when I wanted to use a certain club. I was very pleased with how I played because you have to hit a lot of greens with this course.''
Luiten, who won his first European Tour title at the Johor Open in 2011, carded the round of the day with a 7-under 64.
''The closing holes are tough, but the wind was different out there today,'' Luiten said. ''They were playing downwind and that makes a big difference. It is always nice to make an eagle on a par four, which I did at 15.''
Lee Slattery, who was in second place overnight, endured a hard time after finding water twice on the par-3 third on his way to a 5-over 76.
Ryder Cup hopeful Paul Lawrie could manage only a round of par 71 and was in a tie for 26th going into the final day.
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 three-foot putt for par at 17.
The 19-year-old Manassero, who qualified for the U.S Open on Monday, apologized for his actions after his round, in which he carded 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.''