Chonburi - Charl Schwartzel banished the injury woes that have marred his season to take the overnight lead at the Thailand Golf Championship on Thursday, galvanising his bid to better last year's second place to Lee Westwood.
The 2011 Masters champion hit seven birdies in a flawless 65 in steamy conditions at the Amata Spring course as he appeared to be over the rib injury that has seen his form dip alarmingly this season.
Leading the chasing pack was home star Thitiphun Chuayprakong, who said a new coach working on the mental side of his game had fuelled his promising 66, while surprise packages Daniel Chopra and Javi Colomo finished one behind at five under.
"I'm just playing injury-free... that's allowing me to swing the club much better. My consistency is coming back and that's the key for me," said the South African Schwartzel, who has had just two PGA Tour top ten finishes this season.
"When you are playing with injury, you always try to protect the injury and the consequence is a bad swing."
Masters champion Bubba Watson led a clutch of players on four under, defying the furnace-like mid-morning temperatures and teasing the crowd with a glimpse of his renowned buccaneering "Bubba Golf", by holing a birdie, eagle then birdie after the turn.
"It was a solid round but I made a few mistakes," said the left-handed American, adding the winner will have to "beat the heat" as well as the high-class field.
Ryder Cup winner Sergio Garcia returned to the clubhouse with a three under 69, with wayward putting on the back nine derailing what looked set to be a challenge for the overnight lead.
"Hopefully I can play a little bit better on Friday and shoot a good score and get myself in a good position for the weekend," the Spaniard said.
It was a frustrating day for defending champion Westwood, who had said he was capable of repeating a miraculous first round 60 that spurred his 2011 victory, but found his putting let him down to send him in at two under.
A bogey at the last took the sheen of a solid, if unspectacular, round from the world number six, and he was clearly unhappy with his effort as he trudged into the clubhouse without speaking to waiting reporters.
As the sun dipped beneath the palm tree-lined course there was plenty of cheer for local fans, with Thitiphun joined by veterans Thaworn Wiratchant - who leads the Asian Tour Order of Merit - and Thongchai Jaidee very much in the chase, at three under.
"It's a home course for us," said a delighted Thongchai after a thrilling back nine that included four birdies, the pick of them an audacious chip in at the thirteenth.
"We have a lot of support here, so we're all relaxed. It would great to see a Thai win."
In a star-studded field American world number 25 Hunter Mahan was still in contention at one under, while Japanese sensation Ryo Ishikawa was one shot better off after going round with Bubba Watson.
Scores after the first round of the Asian Tour Thailand Golf Championship at the par-72 Amata Spring Country Club on Thursday:
65 - Charl Schwartzel (RSA)
66 - Thitiphun Chuayprakong (THA)
67 - Daniel Chopra (SWE), Javi Colomo (ESP)
68 - Bubba Watson (USA), Mo Joong-Kyung (KOR), Park Hyun-Bin (KOR), Masanori Kobayashi (JPN), Kiradech Aphibarnrat (THA)
- Wade Ormsby (AUS), Darren Beck (AUS), Annop Tangkamolprasert (THA),
Serigo Garcia (ESP), Luke List (USA), Prom Meesawat (THA), Thongchai
Jaidee (THA), Thawon Wiratchant (THA), Jbe Kruger (RSA), Juvic Pagunsan
(PHP), Jyoti Randhawa (IND)
70 - Darren Clarke (NIR), Lee Westwood (ENG), Ryo Ishikawa (JPN)
71 - Hunter Mahan (USA)