Sweden, Thailand and Australia secured their semi-final berths at the LPGA International Crown on Friday as the United States edged close with two wins over England.
Sweden and Thailand remained perfect with another pair of wins each. Madelene Sagstrom and Maya Stark defeated China's Yin Ruoning and Lin Xiyu 2&1 and Anna Nordqvist and Caroline Hedwall defeated Liu Yu and Liu Ruixin by the same score to put the Swedes a point clear of the United States atop Pool A.
Thailand top Pool B with four points after Patty Tavatanakit and Atthaya Thitikul beat South Koreans Ko Jin-young and Kim Hyo-joo 3&2 while sisters Moriya and Ariya Jutanugarn downed Choi Hye-jin and Chun In-gee 2&1.
"I love this course," Tavatanakit said. "I feel like it is a really tight course, but it doesn't seem tight for me just because I really love this course and I feel like I can really get it going with a lot of confidence.
"That really helped with my flow, too. That's why I really hit it well."
Australia secured their spot from Pool B with a win and one tie against Japan on Friday.
Minjee Lee and Stephanie Kyriacou beat Japan's Nasa Hataoka and Ayaka Furue 2-up while Hannah Green and Sarah Kemp tied their match with Hinako Shibuno and Yuka Saso.
The event at TPC Harding Park is the fourth edition of the eight-team tournament featuring four-woman teams from eight nations.
Four-ball (best ball) matches continue through Saturday, and the top two teams in each will play semi-finals consisting of two singles and foursomes match on Sunday, to be followed by a final in the same format.
"I feel like we've had a lot of fun this week, and I feel like that's been working to our advantage," Nordqvist said.
She and Hedwall birdied five of the first six holes to go 3-up on the way to victory over Liu and Liu.
Japan was the only team that made a switch to their partnerships from the first day, but they were still unable to get a win that would keep them in the hunt.
Australia's Kemp said the chilly temperatures at Harding Park required some adjustments.
"We grew up playing in just a shirt, that's it, and shorts. So this is very different for us," Kemp said. "When I have this many layers on I'm probably at least half a club less, and it got really windy out once we came out the back."
The Americans, who split their first two matches with China on Thursday, are on the brink of advancing after Nelly Korda and Lilia Vu beat England's Alice Hewson and Liz Young 2&1 while Lexi Thompson and Danielle Kang beat Bronte Law and Jodi Ewart-Shadoff 3&2.
Thompson sealed the win with a 12-foot birdie putt at the 16th.
"It was breaking quite a bit so I played it about two and a half cups out," Thompson said. "(It was) a little bit uphill, so I knew I could be a little aggressive with it."