Serena Williams celebrates beating Japan's Kimiko Date-Krumm in their third...

Serena Williams celebrates beating Japan's Kimiko Date-Krumm in their third round women's singles match on Day Six of the 2013 Wimbledon Championships. (June 29, 2013) Credit: Getty Images

WIMBLEDON, England -- For Serena Williams, it was a long day into night, but the only journey involved was from one tennis court to another.

Along with the figurative trip to Wimbledon's fourth round.

Williams, the defending champion and No. 1 seed, and 42-year-old Kimiko Date-Krumm were supposed to be the fourth match on Court 1 Saturday. But at about 8 p.m. -- it gets too dark to play at about 9:15 -- officials hurriedly shifted them to Centre Court, where there's a roof and lights.

After that decision, Williams needed only 1 hour, 1 minute to overwhelm Date-Krumm, 6-2, 6-2, for her 34th consecutive victory in the 600th match of her career.

"What a better place to win the 600th match," Williams said, "on Centre Court at Wimbledon. It was awesome."

Eleven years younger than Date-Krumm, Williams had talked about her opponent's flat balls, an asset on grass. But Serena was everywhere and finished with eight winners, compared with Date-Krumm's four.

"I'm finally starting to feel better," Williams said. "It was such a long clay-court season. The first match [Tuesday], I was feeling really awkward.

"I'm getting there. I always like to peak toward the end of the second week. It was unbelievable playing under the closed roof. I don't think it gets better for me than under a closed roof on grass."

Three other American women played. Sloane Stephens made an amazing comeback to defeat Petra Cetkovska, 7-6, 0-6, 6-4. The match was halted by darkness Friday night after the second set and the third set began with Cetkovska going ahead 2-0, a string of eight straight points.

"I lost focus," said Stephens, the 17th seed. "It was tough coming back. This was weird, coming out [Saturday] for one set. It was like practice."

Madison Keys, an 18-year-old from Illinois, and Alison Riske, a wild-card entrant from Pittsburgh, both lost. Keys was beaten in her first Wimbledon, 7-5, 4-6, 6-3, by Agnieszka Radwanska, who last year made it to the final against Williams. Riske was defeated by Kaia Kanepi of Estonia, 6-2, 6-3.

"I just wanted to do better than last time," Keys said, referring to a 6-1, 6-1 loss to Radwanska in 2012. "I was impressed with my serving. I had a lot of aces and it got me out of tight situations."

Williams' counterpart in the men's draw, defending champion Novak Djokovic, won, 6-3, 6-2, 6-2, over Jeremy Chardy. That match preceded the suddenly rescheduled one with Williams and Date-Krumm.

"It's great under the roof," Williams said, "it's like a dome. I love the sound of the ball."

Djokovic played with the roof open, so he wasn't concerned with sounds, just accuracy. "I felt great from the start 'til the end," Djokovic said. "I had that super focus. I saw the stats, that I won 100 percent of the first serves, and I served over 80 percent the whole match. That was incredible for me."

Laura Robson became the first British woman to reach the final 16 since Samantha Smith in 1998, rallying from a near straight-sets defeat to stun Marina Erakovic, 1-6, 7-5, 6-3. She joins Andy Murray, who didn't play Saturday, to give the All England Club two Brits remaining after a wild first week.

The weather Saturday included a blue sky with plenty of sunshine, the best day of the week that mostly was cold and wet. Even with the long days over here, the daylight disappeared before Williams could get on the court where she wasn't originally scheduled.

No problem. Day or night, indoors or out, she rolls on.

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