The New Zealand 19-year-old shot a six-under-par 65 to move to eight-under overall in the tournament
The New Zealand 19-year-old shot a six-under-par 65 to move to eight-under overall in the tournament at TPC Kuala Lumpur.
However, play was delayed for more than four hours by heavy rain and eventually halted with several leading golfers yet to finish their rounds, which will be completed Sunday morning.
China's Feng Shanshan holed six birdies and an eagle to go to seven-under on the day through 17 holes before play was stopped.
She provisionally topped the leaderboard at 13-under, followed by Anna Nordqvist of Sweden at 12-under and South Korea's Amy Yang another stroke back.
Nordqvist and Yang still have three holes to play from the third round.
The clubhouse lead officially belonged to Suzann Petterson of Norway, who shot a 66 to move to nine-under overall.
She was the highest golfer on the leaderboard who had finished the round.
Mother Nature?s interference meant that 15 golfers will be making up suspended rounds Sunday morning.
Ko made it over the line despite the lengthy delays, and will try to catch the leaders for her first title since the Marathon Classic in July.
That's an uncharacteristic drought for the young phenom, who has struggled to break out on the leaderboard this week.
"I've been striking the ball pretty well. I'm making a few putts here and there but the putts that didn't drop on the first day kind of have been dropping the past two days," she said.
"Those little things I think make the difference at the end of the day. But I've still got one long day tomorrow, so I've just got to stick to the same game plan."
Ko is using a local Malaysian caddie after she parted ways with Australian Jason Hamilton earlier this month.
Feng is hoping to reprise her success in 2014, when she won the tournament.
"Every week, I know that I actually get pretty close to winning. So this week, I know that my record here is really good in Malaysia and I've won here before," said Feng.