In a battle of the last two Wimbledon champions, four-time titlist Serena Williams took out defending champ Petra Kvitova to reach the semifinals at The Championships.

The sixth-seeded Williams doused the No. 4 seed Kvitova in 6-3, 7-5 fashion under the roof on Centre Court at the All England Lawn Tennis Club. It was raining on the outside courts while Williams and Kvitova were dueling in their high-quality quarterfinal.

Williams bounced the big Czech in 84 minutes behind by some brilliant serving. The former world No. 1 star hammered 13 aces, avoided any double faults, and allowed only one break-point chance, which Kvitova was unable to convert on Day 8. Williams smacked three aces in the final game to seal the deal.

A determined Williams won the first set easily and got the key break she needed in the second to grab a 6-5 lead when the lefthanded Kvitova netted an errant forehand. In the next game, or the final game of the match, Williams converted on her first match point by unleashing an unreturnable serve.

Williams also bested Kvitova in a semifinal here at Wimbledon two years ago.

A pleased Williams, who was forced to escape a pair of tough three-set matches in her previous two outings, was asked if she stepped up her game Tuesday.

"Yeah, I had to today playing the defending champ," she said after the big win. "I'm going to have to [step it up again] if I'm going to win the title. There's a lot of people vying for it still."

Williams' final-four opponent will be second-seeded Australian Open champ Victoria Azarenka of Belarus or unseeded Austrian slugger Tamira Paszek.

The 30-year-old Williams owns 13 majors titles, including four in this London suburb, where she's also a two-time runner-up. The powerful American will appear in her eighth Wimbledon semifinal (6-1) on Thursday.

Williams was joined in the semis by eighth-seeded German Angelique Kerber, who outlasted her 15th-seeded compatriot Sabine Lisicki 6-3, 6-7 (7-9), 7-5 on the retractable-roof-covered Centre Court. Lisicki was a semifinalist here last year.

Kerber needed five match points to finally put away Lisicki, who ousted world No. 1 Maria Sharapova here on Monday.

Lisicki saved three match points in the second set, including a second one when she safely landed an easy forehand volley to cap a super rally between the two Germans in the 10th game of the stanza. Lisicki went on to win that game and level the set at 5-all.

Kerber lost a third match point when Lisicki ripped a backhand winner to level the second-set tiebreak at 7-7.

In the deciding see-saw third set, Lisicki broke for what appeared to be a safe 5-3 lead, as Kerber sulked around the court for most of the stanza. But Kerber broke right back, then held, broke Lisicki again for a surprising 6-5 advantage, and closed out the match with an easy hold. Lisicki saved a fourth match point with a forehand winner down 5-6 in the third, but Kerber finally connected on a fifth match point when Lisicki sent one final backhand wide on tennis' most-famous court.

Kerber prevailed in 2 1/2 hours despite a 10-ace effort from the big-serving Lisicki. Kerber, however, broke Lisicki eight times, while the Day-8 loser settled for five breaks of serve. Lisicki struck 38 more winners (57-19), but also piled up 37 more unforced errors (50-13).

The 24-year-old Kerber improved to 16-1 in three-set matches this season, with her only loss coming in a grass-court final in Eastbourne two weeks ago.

Kerber will appear in her first Wimbledon and second career Grand Slam semifinal. She also reached the semis at last year's U.S. Open.

The lefthanded Kerber will face the Agnieszka Radwanska-Maria Kirilenko winner on Thursday.