Japan’s Ai Miyazato put on a performance to match the heat as she fired a five-under 67 to take the first round lead in the $1.5 million LPGA Thailand tournament on Thursday.

Miyazato, who won the same tournament two years ago, took a one-shot lead over Australian veteran Karrie Webb, as well as Sweden’s Anna Nordqvist and Koreans Amy Yang, Se Ri Pak and Na Yeon Choi who all shot 68.

“Four birdies and no bogeys. I’m pretty happy with that,” said Webb, currently ranked 20th in the world.

“The conditions, apart from the heat, were good,” she said, speaking for many players who battled sweltering conditions.

“I was a little scratchy on the front nine, but on the back nine I started to hit my irons better and gave myself quite a few birdie chances.”

Miyazato set the Siam Country Club course alight with five birdies and no bogeys.

“I’m really excited, but I feel very tired. It’s been a long day. I think it must be the heat,” said the Japanese player, who hardly made a mistake in her round.

“I’ve been working on my short game and it seems to be paying off. I like this course, but the greens are tricky.”

Pre-tournament favourite and world number one Yani Tseng of Taiwan could not find her rhythm and had to be content with a one-over 73.

American Stacy Lewis had looked to be poised to take the first round lead as she arrived at the 18th hole on five-under.

But a disastrous triple bogey eight at the final hole, in which she ran into bunker trouble, ruined what had been a good day.

Her anguish was apparent as she threw her putter into her bag in disappointment at the 18th, having to settle for a 70 in joint ninth place.

Among the crowd favourites Paula Creamer had a roller-coaster start. Despite shooting a hole in one at the 12th, she ended with a relatively modest round of even par 72.

Last year’s runner-up, Michelle Wie, struggled with a 75.

American teenage prodigy Alexis “Lexi” Thompson did not have the best of days with a 73 but she is only five off the lead.