Caroline Wozniacki advanced to the semifinals at the WTA Finals by beating top-ranked Simona Halep 6-0, 6-2 Wednesday.
The former No. 1 from Denmark, who made only seven unforced errors in the match, took advantage of the slow court, using the time to set up her shots and cover more ground.
In the first set, Halep won only 10 of the 35 points played, and Wozniacki never faced a break point.
"I don't think it's ever easy when you play a world No. 1," Wozniacki said. "I think this court is great for the all-around player who can play both aggressive and defence."
The sixth-seeded Wozniacki saved the one break point she faced in the fifth game of the second set. She broke Halep's serve twice in the second set.
"I think it was one of my bad days," Halep said. "I made too many mistakes and she didn't miss."
Wozniacki improved her career record over Halep to 4-2. She won both of their meetings this season, although the other was a three-setter in the quarterfinals at Eastbourne.
Wozniacki is now 2-0 at the season-ending tournament, while Halep is 1-1.