(REUTERS) - Women's world No. 2 golfer Lydia Ko took control of the LPGA Taiwan Championship, with a sizzling performance on the back nine that gave the 18-year-old a four-stroke advantage going into Sunday's final round.

Ko, who trailed South Korean Ji Eun Hee by a stroke at the halfway stage, carded a five-under par 67 in the penultimate round on Saturday for a three-day total of 13-under 203.

She made the turn at even-par for the day with a double bogey on the fifth hole and another dropped shot on the eighth cancelling out her three birdies.

But Ko, who will reclaim the top spot in women's world rankings from South Korean Park In Bee with a win or a runner-up finish, harvested five shots on the back nine to extend her lead.

"On this course anything can happen," she was quoted as saying by the LPGA website (www.lpga.com). "It's hard to say, 'hey I've got the trophy today.' I've still go to play a lot of good golf tomorrow. There's still 18 holes to go."

A victory on Sunday will also make Ko the youngest player to earn 10 wins on the LPGA Tour.

Ji (72) was alone in second at nine-under, with Briton Charley Hull on third a stroke further adrift.