Pelle Edberg's local knowledge continued to serve him well as he opened up a two-shot lead early on day two of the True Thailand Classic Presented by Chang.
The Swede has an official affiliation with Black Mountain Golf Club, spending large parts of the winter practising at the layout which is a member of the network of European Tour Properties.
That local know-how came to the fore in an opening 65 on Thursday and Edberg, who is searching for a first European Tour win in his 200th event in Hua Hin, turned in 33 in his second round to get to ten under.
That gave him a two-shot advantage over Scotland's Simon Yates, another Black Mountain affiliated player, Thailand's Panuphol Pittayarat, South African Shaun Norris and overnight leader Peter Uihlein, who was yet to tee off.
Edberg made birdies at the fifth, sixth and ninth and will be in confident mood heading into the back nine, having played that half in 30 on the opening day.
Yates, who is based in Thailand, was three under for the day through 13 holes having made gains on the first, second, fifth and 13th, with a single blemish on the third.
Norris, starting on the tenth, had birdies on the tenth, 17th and 18th to turn in 33 while Pittayarat was four under for the day through 13 holes.
India's Chiragh Kumar was at seven under for the week after 12 holes having picked up three shots on Friday, alongside American David Lipsky, who was two under after ten holes.
Piya Swangarunporn was two under for his round through 12 holes to sit a further shot back, while playing partner Benjamin Hebert was making a move at five under for the round and the tournament.