The ever-present smile sported by Caroline Wozniacki gets bigger every day, and no wonder. The 19-year-old from Denmark, who is the Family Circle Cup's No. 1 seed and No. 2-ranked player in the world, beat 2006 champion Nadia Petrova on Friday, cruising to a 6-3, 6-4 victory.

That puts Wozniacki in the semifinals for the second straight year. In last year's Family Circle Cup, Wozniacki lost to Sabine Lasicki in the final, 6-2, 6-4.

"I feel like I'm playing very well," Wozniacki said. "I'm very confident, and I've got some good results with my play. I'm very happy about that."

The opening set was a roller-coaster for both players, with Wozniacki jumping out to a 2-0 advantage, only to see Petrova, a 27-year-old from Russia ranked No. 18 in the world, win the next two points. But Wozniacki won the next three, including a break point when Petrova double-faulted twice.

Wozniacki broke Petrova on the fifth point of the second match and then held serve to put Petrova away. She improved to 2-1 all-time against Petrova.

Wozniacki said the points were shorter today than in her 6-3, 6-1 win Thursday over No. 16 Patty Schnyder. She is trying to win for the second straight tournament, having successfully defended her title last week in Ponte Vedra, Fla.

Wozniacki, who lost to Kim Clijsters in the final of last summer's U.S. Open, said she got ill later in the year.

"I think that the U.S. Open took a lot of energy out of me," Wozniacki said, adding that she has only been playing big tournaments this year.

"I feel like I've actually been getting good results this year. I'm really happy about the way I'm playing, the way I've been progressing. I feel like I'm on the right track."