Home favourite Piya Swangarunporn was in contention to produce the shock of The European Tour season so far as he moved to the top of the leaderboard during the closing stages of the True Thailand Classic Presented by Chang.
The World Number 798 does not currently hold a card on The European or Asian Tour but looked very much at home at Black Mountain Golf Club as he picked up eight shots in 14 holes to join Scott Hend at the summit.
The Australian turned in 34 to move to 16 under but six birdies and an eagle from Swangarunporn reeled him in, with the duo three shots clear of Belgium's Thomas Pieters.
Swangarunporn's best career result came in Hua Hin as he finished in a tie for third at the Black Mountain Masters on The Asian Tour in 2010, and victory here would come in just his second European Tour event.
Hend is a veteran by comparison, having played in 140 tournaments and he is the hunt for his second European Tour title.
Pieters used his enormous length off the tee to leave a short wedge in and birdie the first while another big-hitter in Shaun Norris joined him at 12 under as two mighty blows allowed him to eagle the par five second.
The two-time winner then holed his bunker shot at the second to join Hend at the top of the leaderboard but the 2014 Hong Kong Open champion soon moved back ahead with a birdie on the same hole.
The lead was back up to two when Pieters dropped a first shot in 39 holes on the third with a three-putt bogey but he picked it straight back up on the fourth, with Hend repeating the trick to restore his cushion.
Swangarunporn had birdies on the second, fourth, sixth and seventh to turn in 32 and move into contention, and when he holed his pitch into the tenth for an eagle, he was just two behind Hend.
He was second on his own when Pieters dropped a shot on the eighth and he reduced the gap to one as he produced a confident putt down the slope to birdie the par five 13th.
A 40-foot birdie putt on the next followed and the 32 year old was at the summit.
Norris and Peter Uihlein were four shots off the lead, with Benjamin Hebert, Grégory Havret, Joost Luiten and Simon Yates a further shot back.