Sami Välimäki's fine form continued on the opening day of the 2023 Thailand Classic as he fired a flawless 64 to lead the way alongside Martin Simonsen.
Finn Välimäki arrived at Amata Spring Country Club fresh from last week's second-place finish at the Singapore Classic, and it did not take him long to get back up to speed.
After starting his first round with three successive birdies, Välimäki made two more on his way to the turn before picking up three shots on the back nine to reach eight under par.
Fellow afternoon starter Simonsen then joined Välimäki at the summit, having carded an eagle, seven birdies and one bogey in his 64.
German duo Alexander Knappe and Yannik Paul were one shot behind the co-leaders in a tie for third, with Thriston Lawrence, Rafa Cabrera Bello, Fabrizio Zanotti and Robin Sciot-Siegrist another stroke further back.
Välimäki got off to a fast start on Thursday, holing his long-range birdie effort at the first before picking up further shots at the second and third for a hat-trick of gains.
The Finn made his fourth birdie of the day at the par-five seventh, having sent his eagle chip close.
The 24-year-old took advantage of the short eighth to reach five under and then a par on the ninth saw him turn in 31.
Back-to-back birdies followed at the 11th and 12th before Välimäki chipped to within a few inches at the long 15th to set up a tap-in birdie which handed him the outright lead on eight under.
He safely parred the remaining three holes to keep his card clean.
Välimäki said: "A really good round. I started nicely and kept it going the whole day.
"I just kept playing and when I started hitting the ball really well, it just made it easy. I was putting really good the whole time and when I got chances I tried to make them."
Simonsen turned in 32 after reeling off birdies at the second, fourth, sixth and seventh before following up a birdie on the tenth with an eagle at the par-five 11th to jump to seven under.
The Dane dropped his first shot of the day at the short 13th but recovered with back-to-back birdies on the 15th and 16th to join Välimäki at the top.
Simonsen said: "It's a great day. I thought it was going to be difficult out there with the wind, and it was. But thankfully I played the par fives really well, which helped. It was great.
"With the wind today, most of them were downwind, so that helped a lot, but you still have to hit the shots. I made it fairly easy for myself on the par fives, that's the key this week, I think."