ZHUHAI, China — CoCo Vandeweghe, Ashleigh Barty and Anastasija Sevastova all advanced to the semifinals at the WTA Elite Trophy on Thursday.

The second-seeded Vandeweghe had 11 aces and saved all four break points she faced to beat Elena Vesnina 6-3, 6-2 in the Bougainvillea group. Vesnina received treatment for a back injury during the match.

"It was tricky in itself, playing against an opponent that's obviously hampered, and you're just trying to kind of manage your own emotions with that and trying to keep your intensity, keep your focus, and that definitely gets a little bit tough," Vandeweghe said.

Barty, who is the youngest player in the draw at 21, beat former top-ranked player Angelique Kerber 6-4, 6-3. The ninth-seeded Australian also beat Anastasia Pavlyuchenkova in the Rose group.

"It was tough group for me because I hadn't actually beaten either of those girls," Barty said. "It's nice to sort of get that revenge this week, but I felt like I served great all week and put myself in a good position in my service games to then be super-aggressive and nice and clear when returning so I can have a little bit more of a crack and see if I can get some of those early breaks in the sets."

Sevastova, seeded fifth, beat Barbora Strycova 6-3, 6-4 in the Camillea group.

The tournament in Zhuhai features the leading players on the women's tour who didn't qualify for the WTA Finals in Singapore last week. The 12-player draw is divided into four groups of three, with the winner of each group advancing to the semifinals.