NEW YORK (AP) -- NEW YORK (AP) - Serena Williams dismissed the idea quickly and completely.
There's no way, the U.S. Open's defending champion and top-seeded woman insisted, that there is any chance of easing up at all or letting her guard down a tad in the quarterfinals.
Really? Even after coming off a much-hyped, intense victory over 15th-seeded Sloane Stephens in the fourth round at Flushing Meadows on Sunday?
"Absolutely not,'' Williams said. "I mean, I've been at this for a long time. So for me in my career, there are no letdowns.''
For eight games, Stephens stayed right with Williams. They put on quite a show during those 40 minutes, hitting serves faster than 115 mph, whipping forehands and backhands that landed near lines, covering a lot of ground to extend points. Stephens already was one of only three players to beat Williams this season, and at 4-all in the first set, another upset seemed possible.
That, though, is when Williams took over. The 20-year-old Stephens' time at the top of tennis may come. For now, the 31-year-old Williams is still as good as it gets, and she won eight of the last nine games to beat Stephens 6-4, 6-1.
"When you give her that opportunity to take that step forward, she definitely makes her move,'' Stephens said. "Unfortunately, today she made her move.''
Williams is 64-4 with eight titles in 2013.
Since a first-round loss at the French Open in May 2012, Williams is 95-5 and has won 13 tournaments. That includes winning three of the past five major championships to raise her Grand Slam trophy total to 16.
The key during that stretch of dominance, she said, has been "consistency, and getting up for every match.''
"Doesn't matter if it's a Grand Slam or if it's a small tournament, just really wanting it,'' Williams added. "Just to do that, knowing that I can do that.''
In the quarterfinals, she will face 18th-seeded Carla Suarez Navarro of Spain, who has never made it to the semifinals at any major tournament. Plus, Williams has won both of their previous matchups.
As if Suarez Navarro needed any other reasons to be wary, Stephens' analysis of her loss to Williams kept returning to a certain theme: "She's No. 1 in the world for a reason,'' Stephens said more than once.
Williams is the only woman to reach the quarterfinals at every Grand Slam tournament this season.
Another American will try to join her at that stage in New York when 23-year-old Alison Riske, who grew up in Pittsburgh, faces Daniela Hantuchova on Monday. The other's women's fourth-round matches on Monday's schedule: No. 2 Victoria Azarenka vs. No. 13 Ana Ivanovic, No. 10 Roberta Vinci vs. Camila Giorgi, and No. 21 Simona Halep vs. Flavia Pennetta.
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