World number three Stacy Lewis remained on top at the Honda LPGA Thailand on Saturday but a series of costly bogeys saw her comfortable lead significantly depleted ahead of the final day.
On Friday Lewis had stormed three shots into the lead during day two of the $1.5 million tournament at the Siam Country Club with a perfect round boosted by eight birdies.
But she was unable to repeat that performance Saturday, shooting a comparatively uninspiring one-over-par 73 marred by four bogeys in the first nine.
Only an eagle on the 15th kept her one shot ahead of South Korea’s Amy Yang who fired off a dependable 71.
Where Lewis struggled, Germany’s Sandra Gal thrived, shooting a masterful six-birdie 68 bringing her up to third place and within a two-shot striking distance of Lewis.
South Korean duo Jenny Shin and Lee Mi-rim will go into the final day in joint fourth place followed by two-time winner Tseng Yani of Taiwan.
Local favourite Ariya Jutanugarn, who experienced heartbreak in 2013 when losing her nerve on the final hole to be edged into second place, had a nightmare third round.
Three bogeys and two double bogeys saw her tumble down the leaderboard.
Defending champion Anna Nordqvist also looks unlikely to catch the leading pack going into the final day in joint eight on 211.
World ranked number two Inbee Park shot an impressive 68 packed with six birdies.
But she remains well out off contention in joint ninth place after a torrid first and second round.