INDIAN WELLS, Calif.—Agnieszka Radwanska will move back up to No. 2 in the WTA rankings, having reached the semifinals of Indian Wells.

Radwanska defeated Petra Kvitova in straight sets in the quarterfinals, coming from 5-2 down in the second set, and will move in front of Angelique Kerber in the rankings.

The 27-year-old won the WTA Finals at the end of last season, and has followed that up with a title in Shenzhen and three semifinal appearances, including at the Australian Open. She agreed that she might be in the midst of the best run of her career.

"I think so, especially in that [the] offseason is a big break," she said. "I'm just so happy that I could just stay in the same level, and [am] playing the same good tennis I was playing."

She attributed it to not doing too much during the offseason and balancing her schedule at the beginning of the season.

"Sometimes we are all thinking more is better, but it's not true, really,” Radwanska said. “I have a really good rest. Didn't do anything throughout three weeks, and then I started very slow. This is the fourth tournament this year [and I’m] playing so good, so I guess the plan was good.”

Back at No. 2 for the first time since 2012, she is in a good position to keep up her ranking.

"It's always a good feeling to be back in this position," she said. "And now I have the opportunity that I'm definitely not really defending much points until the grass [season]."

Radwanska will play Serena Williams in the semifinals.