Veteran star Prayad Marksaeng struck a seven-under-par 65 at the inaugural Chiangmai Golf Classic on Thursday, crediting his form to a change in his putting grip partway through his round.
The 47-year-old local hope, chasing his sixth Asian Tour victory, left four-time major winner Ernie Els in the shade as the South African battled to a 69 with a short putter in his bag for the first time since the end of 2011.
China's Hu Mu put in a solid 66 to tie for second place with Thai Prom Meesawat and American Jonathan Moore in the US$750,000 (22.5 million baht) Asian Tour event.
Prayad switched to the cross-handed putting grip after shooting pars over four holes and then went on to make five straight birdies to turn in 31. He carded three more birdies against a lone bogey to top the leaderboard.
"For the first few holes, I couldn't putt. I didn't have a good feel," he said in a statement released by organisers.
"After I finished the fourth hole, I changed my grip to the cross-handed grip and then I kept making birdies," added Prayad, whose last Asian Tour victory was in 2007.
"The greens here are very quick. I talked to my caddie and we checked the lines together on every hole. Normally, I read my own lines. This course is good. I feel comfortable here as it's very tree-lined, very similar to Japan."
British Open champion Els, meanwhile, shot a bogey-free three-under-par 69 to sit four off the lead.
Els used a conventional putter for the first time since the end of 2011, instead of his favoured belly device which golf authorities are considering banning.
"I thought it was good," the South African said of the short putter.
"I missed some greens so I had to up and down a few times and there were some good putts which I had to make."
Scores after round 1 of the Chiangmai Golf Classic being played at the par-72 Alpine Golf Resort course:
65 - Prayad Marksaeng (THA)
66 - Prom Meesawat (THA), Hu Mu (CHN), Jonathan Moore (USA)
67 - Pawin Ingkhapradit (THA), Jason Knutzon (USA), Digvijay Singh (IND)
68 - Carlos Pigem (ESP), Bryce Easton (RSA), Jazz Janewattananond (THA), Matthew Stieger (AUS), Panuwat Muenlek (THA), Scott Hend (AUS), Thitiphun Chuayprakong (THA), Adam Groom (AUS)
69 - Ernie Els (RSA), Thongchai Jaidee (THA), Lin Wen-hong (TPE), Siddikur (BAN), Shiv Kapur (IND), Pariya Junhasavasdikul (THA), Lin Wen-tang (TPE), Yang Y. E. (KOR), David Lipsky (USA), Baek Seuk-hyun (KOR), Antonio Lascuna (PHI).