DP World Tour news: Scandinavian duo share Thailand Classic lead after first round

Valimaki carded eight birdies in a flawless 64 while Simonsen recorded an eagle, seven birdies and a solitary bogey as 82 of the 132-strong field broke par at Amata Spring Country Club.

"It's a great day," Simonsen said. "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.

"Most of them were downwind, so that helped a lot, but you still have to hit the shots.

"I haven't played the way I've scored the last two weeks, so it's been very, very frustrating for me. I feel like I've been playing better than what the scores have said. I'll just keep doing what I'm doing and eventually it'll be OK."

Simonsen and Valimaki enjoyed a one-shot lead over German duo Alexander Knappe and Yannik Paul, with home favourite Kiradech Aphibarnrat three shots further back after carding six birdies and a double bogey on the 14th.

Scotland's Robert MacIntyre was also part of the large group on four under par after finding a solution to his recent putting issues.

"The last four weeks have been tough on the greens," the left-hander said. "I've done a bit of work on Tuesday and realised it was more mental, not technique.

"It was about freeing myself and that's what I've done. I've changed my pre-shot routine a touch and just trusted my instincts and what I do best, that's putting a good stroke on it and hoping it goes in.

"I'm driving it well. I've really just been waiting on the putter to turn up the last few weeks. Hopefully today is a good sign."