Lewis powers into lead as Tseng toils in Thailand

American Stacy Lewis stormed to three-shot lead in a near flawless first round at the Honda LPGA Thailand on Thursday, while world number one Tseng Yani endured a horror start to her title defence.

Third-ranked Lewis blistered to the top of the leaderboard with a nine under 63, lit up by an eagle and eight birdies — including a hat-trick on holes 5,6 and 7 — dropping just one shot on her way back to the clubhouse.

The American, who was dogged by a curvature of the spine as a teenager, has amassed more than $4 million in a career marked by five victories so far and appears well set to add to that tally at Pattaya’s Siam Country Club.

She leads second-placed Karine Icher of France, who notched six birdies without dropping a shot in her six under 66, with Scottish veteran Catriona Matthew leading a clutch of players a shot back at five under.

But it was a torrid day for 24-year-old world number one Tseng, who is bidding for her first victory in nearly a year — a barren spell which has seen her 106-week hold on the top ranking chiselled away to a narrow 1.29 points lead over South Korea’s Choi Na-Yeon.

Tseng started the day badly, dropping a shot on the par five first and struggling throughout her round with a further four bogeys, only slightly redeemed by birdies on 15 and 18 which sent her back with a three over 75.

It was a far cry from last year’s dominance of the Thai event, the second straight win of the competition, which looked set to propel Tseng to another all-conquering season on the tour.

But the victories dried up in March, raising pressure on the young star.

Tseng got off to an encouraging start to the 2013 season last week, finishing second at the Women’s Australian Open, behind winner Shin Ji-Yai but ahead of teenage prodigy Lydia Ko.

New Zealand amateur Ko, 15, who became the tour’s youngest winner last year, may well turn the tables in Pattaya after posting a solid three under 69, with two late bogeys on 16 and 17 preventing her from ending the day even closer to the leader.