Yani Tseng was only one of seven players to beat par in the second round.
INCHEON, South Korea (AP) -- Na Yeon Choi of South Korea shot a 71 and Taiwan's Yani Tseng had a 70 to share the lead at 5-under par after a wet and windy second round of the LPGA Tour's KOLON Championship on Saturday.
Choi and Tseng finished at 139 and were among seven players to go under par for the round as poor weather forced play to be suspended for almost an hour.
The 22-year-old Choi led for most of the round before returning from the rain delay and bogeyed the par-3 17th hole to allow Tseng a share of the lead.
Sweden's Maria Hjorth (72) and South Korean Jimin Kang (73) were tied at 4 under for the tournament.
First round co-leaders Meaghan Francella and Anna Grzebien of the United States dropped six strokes and 10 strokes, respectively, to fall to the middle of the pack.
But the challenging weather didn't stop Choi, who made four birdies on the front nine before weather forced the suspension of play.
"My putter was working on the front nine but it was hard to focus as the wind and rain got stronger on the back nine," Choi said.
Tseng and South Korea's In-Kyung Kim were the only players to shoot a 70 for the low-round of the day.
More inclement weather is forecast for Sunday's final round. The 2007 tournament was shortened to 36 holes due to unplayable course conditions.
Choi earned her first victory on the LPGA Tour at the Samsung World Championships last month after finishing 11th on the LPGA money list last year in her rookie season.
Choi also has four wins on the Korean LPGA Tour, which is co-sanctioning this week's tournament.
Five Koreans rounded out the top five at 3 under; Inbee Park, Eun-Hee Ji, Ran Hong, Song-Hee Kim, and Bo-Kyung Kim.
The shot of the day went to Jiyai Shin of South Korea. The LPGA money leader holed a shot from the bunker on the sixth hole after pulling her approach shot left. Shin was at 1 under.
Lorena Ochoa was 10 strokes off the lead after a second-round 77, tied for her second-worst round of the year.
The LPGA Tour moves to Japan next week for the Mizuno Classic.