Thomas Pieters made the big move on day three of the True Thailand Classic Presented by Chang as the field bunched up at Black Mountain Golf Club.
Australian Scott Hend held a share of the overnight lead and he hit the front on his own at 13 under courtesy of a birdie on the par five second, but that was just two shots clear of Pieters who picked up six shots in his first 13 holes.
The big-hitting Belgian claimed back-to-back wins at the D+D REAL Czech Masters and KLM Open last summer and six birdies on Saturday catapulted him into contention for a third European Tour title.
It was an encouraging return to form for the 24 year old who had missed his last two cuts and opened with a 73 on Thursday.
Hend's birdie on the second handed him a one-shot lead over local favourite Panuphol Pittayarat, who made a gain on the same hole, while Swede Pelle Edberg was alongside Pieters after dropping a shot on the second.
American Peter Uihlein was then at ten under through five holes after a birdie on the first, a shot clear of Benjamin Hebert, Thongchai Jaidee, David Lipsky, Joost Luiten and Shaun Norris.
Thai Jaidee had an eagle on the sixth as he turned in 33, while Dutchman Luiten was also three under for the day through eight holes.
France's Hebert had two birdies and a bogey in his first five holes and Norris and Lipsky were both level par through four.
There was then a group of ten players five shots off the lead at eight under.
