AUCKLAND, New Zealand -- Top-seeded Coco Gauff has beaten Lin Zhu of China 6-3, 6-2 to reach the semifinals of the ASB Tennis Classic in a tournament that has been dogged by bleak weather and diminished by waning star power.

Venus Williams, second-seeded Sloane Stephens and former US Open champion Emma Raducanu all were beaten in the second round, and for the third day in a row, matches were moved indoors Friday because of rain and played without spectators.

Another seeded player, third-seeded former US Open finalist Leylah Fernandez, was beaten 6-4, 6-2 on Friday by Belgian qualifier Ysaline Bonaventure.

Gauff deserved an audience for her impressive win over Zhu, which she achieved in only 76 minutes and earned her a ninth semifinal of her career. The American hasn't dropped a set at the tournament.

Zhu has faced Americans in each round of the tournament so far, beating Madison Brengle in the first round and Williams in three sets in the second round on Thursday.

But Gauff was in top form Friday. She served eight aces, won 89% of first-serve points and didn't face a break point, converting three of 13 chances to break on Zhu's serve.

"It was a really great match for me," Gauff said. "Each match I'm improving, and that's what I love to see. She's not an easy player obviously, beating Venus yesterday, and she was probably coming off a lot of momentum. But I was glad I was able to stay focused."

Gauff adapted better than most to the indoor courts, which players say are faster and slicker than those outdoors. Her game seemed unaffected, and she played her groundstrokes with confidence.

But Gauff missed the crowd.

"It's not the ideal conditions to play in, no fans and I'm sad they can't see the matches," she said. "But at the end of the day it's tennis and I'm glad to be on the court."

Gauff's view contrasted with that of Raducanu, who blamed the indoor courts for the ankle injury she suffered during her second-round match on Thursday.

Raducanu, who beat Fernandez in the 2021 US Open final, said the courts were too slippery. She rolled her left ankle in the second set of her match against Slovakian qualifier Viktoria Kuzmova and couldn't continue.

Kuzmova bowed out Friday after a 6-3, 6-2 loss to seventh-seeded Danka Kovinic.