Mentally tough Zvonareva passes test

John McEnroe, never one to shy away from predictions, said after the quarterfinals that he would stand on his head if Serena Williams didn't win the Wimbledon title this fortnight. He must have been a little edgy Thursday when Williams fell behind an early break to Czech left-hander Petra Kvitova. The 12-time Grand Slam champion recovered, of course.

ESPN.com grades the Wimbledon semifinalists, with Williams' next opponent, Vera Zvonareva, leading the way.

Vera Zvonareva

There was a moment in Zvonareva's 3-6, 6-3, 6-2 win over Bulgarian Tsvetana Pironkova when you thought the Russian might revert to type and implode. Zvonareva had just missed a backhand into the net facing set point, undoing a minicomeback from 40-0 down. She berated herself.

What would happen during the changeover?

Nothing, as it turned out.

"I've been in a lot of different situations in the past, and I think I know how to turn the matches around much better now," Zvonareva said.

Zvonareva used her all-court game to rally past Pironkova, totaling 31 winners and 13 unforced errors. She went 29-for-35 on net approaches.

Grade: A-. She's looking mentally tough.

Serena Williams

Most expected Williams to blow away Kvitova. Except Williams, that is. Williams said before the match that she had watched Kvitova earlier in the tournament and was impressed.

Williams served well at key moments again and won 80 percent of her points behind her first serve. She took advantage of a loose game to break back in the first set and ended up prevailing 7-6 (5), 6-2. Her defense was outstanding.

Plus, she doled out a rare compliment. "She does everything good," Williams said of Kvitova.

Williams, however, didn't start well.

Grade: B+. She was workmanlike, not dominant.

Petra Kvitova

Reaching the semis was no fluke for Kvitova, a tall, hard-hitting baseliner whose game resembles that of compatriot and men's semifinalist Tomas Berdych. Third-seeded Caroline Wozniacki, a slightly rejuvenated Victoria Azarenka and three other previous Grand Slam quarterfinalists (at least) were among her victims.

Kvitova started well against Williams, especially with the cross-court forehand. She was the one standing closer to the baseline. The 20-year-old was even one point from leading 5-2 in the opening set.

She predictably fizzled in the second.

"I think it was a great match for me," Kvitova said.

Grade: B. She made it closer than we thought.

Tsvetana Pironkova

Pironkova picked up where she left off against Venus Williams, ripping backhands and throwing in big serves. As with Kvitova, there were no nerves.

But she began to wobble early in the second. When Zvonareva broke for 3-2, it unsettled Pironkova. Zvonareva was suddenly the one doing the dictating.

Here's hoping 82nd-ranked Pironkova isn't a one-Slam wonder.

"There are many things I should work on, and I will do it with pleasure," she said. "Now I have lots of motivation."

Grade: B-. The magic dissipated.