Williams and Wozniacki reach Auckland semifinals

Top-seed Serena Williams struggled with a swirling breeze before beating Germany's Laura Siegemund 6-4, 6-3 Friday to reach the semifinals of the ASB Classic. As was the case with her three-set win over Christina McHale in the second round, Williams was never fully in control of the match. She came from a break down in the second set to win in just under 90 minutes.

But she was able to step up at crucial times. Williams had five break point chances and converted three. Siegemund had seven and converted one. Siegemund, who beat American teenager Coco Gauff in the second round, stretched Williams with her variety and placement but couldn't match Williams' power from the baseline.

"She was an incredibly tricky player and the conditions really didn't help," Williams said. "But, oh my God, it's good to get through that. "The body's feeling great. I came in here before the tournament last year and said I wanted to play singles and doubles here. So I'm happy, I knew what I was going to be up against and I'm happy to still be in the tournament."

Caroline Wozniacki progressed to the semifinals with a 6-1, 6-4 victory over two-time defending champion Julia Goerges of Germany.

"I've had so many tough matches against Julia in the past and I knew this one was going to be tough as well," Wozniacki said. "I've been serving well this week so hopefully it can continue."

Wozniacki's semifinal opponent will be Jessica Pegula of the United States who beat Alize Cornet of France 6-0, 3-2. Cornet was forced to withdraw with a thigh muscle strain.