Serena Williams took down Dutch qualifier Arantxa Rus to reach the Western and Southern Open third round in New York.
She won 7-6 (8-6) 3-6 7-6 (7-0) in almost three hours.
"It was a real physical match," said Williams. "I played pretty well, I was being aggressive and hit some good shots, but she just kept fighting."
She will now play Greece's 13th seed Maria Sakkari in the third round.
Meanwhile, fourth seed Naomi Osaka of Japan beat Karolina Muchova 6-7 (5-7) 6-4 6-2. She'll now face 16th seed Ukrainian Dayana Yastremska in round three.
In the men's round, Andy Murray defeated fifth seed Alexander Zverev 6-3 3-6 7-5. It marked his first top-10 win in more than three years.
World number one Novak Djokovic also advanced to third round despite battling neck pain. He crushed Ricardas Berankis 7-6(2) 6-4.
"It has bothered me. I made so many double faults, and he knew exactly where I'm going to serve. It's been four days and it's getting better. I think it's heading in the right direction," Djokovic said.
"Hopefully it will not react with the inflammation after today's match. We'll do everything possible with the physio and then we'll see what tomorrow brings," he added.


Al Nassr secure semi-final spot in AFC Champions League 2 with victory over Al Wasl
Haaland seals crucial win for Man City over Arsenal in title showdown
Bayern Munich win Bundesliga title with victory against VfB Stuttgart
Fils powers past Rublev to win Barcelona Open
Liverpool's Van Dijk scores late winner in derby win over Everton
