Williams, whose older sister, Venus, was one of the few people in the stands, said whatever blips came today "could help me know what not to do next time". That'll be Sunday against Stephens, the 2017 US Open champion.
It is their seventh matchup; Williams leads 5-1, including victories in the past four meetings, but they last played at the 2015 French Open. Stephens' lone head-to-head victory came all the way back at the 2013 Australian Open.
This calibre of contest certainly doesn't feel as if it belongs in merely the third round at a slam, but that's the luck of the draw this time.
"I'm playing such a good player so early," Williams said, "so I have to bring what I can even more."
What will also be odd: the quiet. All spectators were banned from Flushing Meadows this year because of the coronavirus pandemic.
"I know if there were fans it would be so lit, and I'm kind of sad that we're not playing in front of fans, because it would be so fun," said the 26th-seeded Stephens, who advanced by beating Olga Govortsova 6-2, 6-2. "The atmosphere won't be as big but obviously a big opportunity to play against the greatest player in the world. So, yeah, unfortunate but still fortunate."
Light rain fell during the warmup, so Ashe could be turned into an indoor facility. It remained closed for the match that followed — Andy Murray's straight sets defeat to Felix Auger-Aliassime — and a serious downpour loudly pelted the roof.
Louis Armstrong Stadium was covered during the second set of 2019 men's runner-up Daniil Medvedev's 6-3, 6-2, 6-4 win over 116th-ranked Christopher O'Connell, and stayed that way for two-time Australian Open champion Victoria Azarenka's 6-1, 6-3 victory over No5 seed Aryna Sabalenka.
Matches on all the outside courts were suspended in the evening because of the shower.
Earlier winners included No 2 Dominic Thiem, No 11 Karen Khachanov, 2014 champion Marin Cilic and unseeded Americans Frances Tiafoe and JJ Wolf. The No 14 Grigor Dimitrov and No 25 Milos Raonic were eliminated.
Johanna Konta, the No 9 seed, lost 2-6, 7-6 (5), 6-4 to Sorana Cirstea, and No 10 Garbiñe Muguruza — who owns two major titles — was beaten 7-5, 6-3 by Tsvetana Pironkova, who took a three-year break from professional tennis to have a son and is in her first tournament since playing at Wimbledon in 2017.
Other women moving on included No 2 Sofia Kenin, who won the Australian Open; No 7 Madison Keys, No 15 Maria Sakkari, No 18 Donna Vekic and No 22 Amanda Anisimova, a 19-year-old American who beat 16-year-old American Kristina Scott.
- AP