matched the world No. 1 for 40 minutes. After that, it was one way.
All in all, it was remarkably compelling and, within individual points, rather evenly played for what turned out to be such a lopsided result.
“I definitely think it was a high-quality match,” said Williams, who has a 64-4 win-loss mark with eight titles this year. “We both came out today to play.”
Asked whether there’s any chance of a letdown after getting past Stephens, Williams replied: “Absolutely not. I mean, I’ve been at this for a long time, so for me in my career, there are no letdowns.”
In Sunday’s other fourth-round women’s matches, No. 3 Agnieszka Radwanska lost 6-4, 6-4 to No. 24 Ekaterina Makarova, and 2011 French Open champion Li Na eliminated 2008 US Open runner-up Jelena Jankovic 6-3, 6-0.
In men’s third-round action, the last of 15 Americans in the field lost, making this the first U.S. Open in history without at least one representative from the host country in the men’s fourth round. Wild-card recipient Tim Smyczek, who is ranked 109th, was beaten 6-4, 4-6, 0-6, 6-3, 7-5 by Marcel Granollers of Spain.
In other men’s third-round action, defending champion Andy Murray struggled with his breathing on a muggy afternoon but otherwise faced little trouble in a 7-6 (2), 6-2, 6-2 victory over 47th-ranked Florian Mayer of Germany.
Murray has won 29 of his last 31 Grand Slam matches, a run of success that includes his first two major titles - at the US Open last September and Wimbledon this July - along with two runner-up finishes.
Former No. 1 Lleyton Hewitt, who won the US Open in 2001 and Wimbledon in 2002, reached the fourth round in New York for the first time since 2006 by defeating 102nd-ranked Evgeny Donskoy 6-3, 7-6 (5), 3-6, 6-1.