South Korea's Jang Ha-na stormed to her second career LPGA victory Sunday when she fired a seven-under-par 65 to win the HSBC Women's Champions Golf Tournament here. Thailand's Pornanong Phatlum finished four stokes behind while world No. 1 Lydia Ko carded a three-under-par to end the tournament tied for 15th with an overall score of 281. Playing in tough humid conditions at the Sentosa Golf Club, world No. 10 Jang fired six birdies, a bogey and an eagle on the 18th to claim the $225,000 winner's check. She said her target was to win two tournaments this year and was surprised she accomplished it so early. "It's amazing," Jang said after her win. "I targeted two wins in 2016 but right now I did it and I'll change my targets to two more wins. But I am comfortable right now." Jang's maiden LPGA title was at the Coates Golf Championship in Florida last month. Her previous best was four runners-up finishes during her rookie season in 2015. With the win, the South Korean is expected to move five places up the rankings, but she said that was not her focus. "I play golf every week and I want to enjoy every tournament," said Jang. "I don't want to think about rankings, the Olympics or titles." Ko had a disappointing first two days but her form kicked in Saturday when she posted a five-under-par 67. The 18-year-old started the final round strongly, firing two birdies and ripping the par-5 7th with an eagle. She shot two more birdies in the back nine but three bogeys in the 13th, 15th and 18th undid much of the good work she had put in. "I had an entirely good front nine, but it is not the best when you end up with a bogey on the last green," said the New Zealander. "Other than that I thought I played solidly this weekend, so there is a lot of positives from this week. "But I feel it could have been better. I did not hole that many putts this week, and I think if I struck the ball a little better on the first two days, I may have been able to reduce a few shots." Pornanong, who was gunning for her first LPGA career win after six years on the Tour, trailed Jang by a stroke entering the final round. The Thai said she was not disappointed after coming close at the Serapong Course. "Ha-na played a very solid round today," said Pornanong. "I just tried my best, but didn't hit it that good. For now, I just want to improve my confidence level for the future and prepare and be ready for the Olympics."