"I went and had Venus talk to her, because Venus can get [through] to Serena better than anyone in the world. . . . When the match was over, I told her, 'Venus: Good coaching! Good coaching!' " Richard Williams said after snapping photos of Serena's victory from his front-row perch in the guest box above a scoreboard.
"I wanted Serena to move her feet a little bit more and to not concentrate on what [her opponent is] doing, but concentrate exactly on what she wished to do," he said. "And that was the only message."
Consider it delivered.
The 30-year-old Williams, bidding to become the first woman at least that age to win a major title since Martina Navratilova at Wimbledon in 1990, turned in her best performance of the tournament against her most difficult foe. After being stretched to 9-7 and 7-5 third sets against less-accomplished women in the two previous rounds, the sixth-seeded Williams was on top of things from the get-go against No. 4 Kvitova.
"You can't play a defending Wimbledon champion or Grand Slam champion and not elevate your game," said Williams, who produced 27 winners and only 10 unforced errors.
Kvitova had won 16 of her last 17 matches at Wimbledon, including 11 in a row since a loss to Williams in the 2010 semifinals.
On Thursday, Williams will play No. 2 Victoria Azarenka, the reigning Australian Open champion, who defeated unseeded Tamira Paszek, 6-3, 7-6 (4), under the roof at night to reach the Wimbledon semifinals for the second straight year. The other semifinal will be No. 3 Agnieszka Radwanska of Poland against No. 8 Angelique Kerber of Germany.
A little before 10 p.m. on Centre Court, Radwanska finished her 7-5, 4-6, 7-5 victory over No. 17 Maria Kirilenko - whose boyfriend, two-time NHL MVP Alex Ovechkin of the Washington Capitals, was in the stands. Earlier, the match was forced off Court 1 because of showers, tied 4-all in the third set.
Kerber was a 6-3, 6-7 (7), 7-5 winner over No. 15 Sabine Lisicki in an all-German matchup. Lisicki saved three match points in the second set, but then let a 5-3 lead slip away in the third against Kerber, also a semifinalist at last year's U.S. Open.
With more rain in the forecast, the roof could be shut again Wednesday, when the men's quarterfinals are No. 1 Novak Djokovic vs. No. 31 Florian Mayer; No. 3 Roger Federer vs. Mikhail Youzhny; No. 4 Andy Murray vs. No. 7 David Ferrer; and No. 5 Jo-Wilfried Tsonga vs. No. 27 Philipp Kohlschreiber.
While defending champion Djokovic, six-time champion Federer, and Youzhny got a chance to rest Tuesday - particularly important for Federer, whose back ached during his fourth-round victory - everyone else slogged through a start-stop-start-stop afternoon of rain delays with the temperature in the low 60s.
The last two American men in the draw were beaten: 10th-seeded Mardy Fish wasted the one-set lead he built before play was suspended Monday and lost to Tsonga, 4-6, 7-6 (4), 6-4, 6-4, and 126th-ranked qualifier Brian Baker's surprising run ended against Kohlschreiber, 6-1, 7-6 (4), 6-3.
Murray eliminated No. 16 Marin Cilic, 7-5, 6-2, 6-3 to prolong Britain's hopes for its first male champion at Wimbledon since 1936; Ferrer easily got past No. 9 Juan Martin del Potro, 6-3, 6-2, 6-3 to earn his debut trip to the quarterfinals; Mayer defeated No. 18 Richard Gasquet, 6-3, 6-1, 3-6, 6-2 to return to the round of eight for the first time since 2004.