No. 11-seeded Venus Williams of the United States advanced to the quarterfinals of the Miami Open on Monday night by upsetting seventh-seeded Svetlana Kuznetzova 6-3, 7-6 (4).
Williams starting quickly, winning the first three games of the match and eventually serving out the first set.
The second set was more challenging. With Williams serving at 5-6, Kuznetsova had two set-point opportunities, but Williams fought off both to force a tiebreaker. Williams then fell behind 4-1 in the breaker before winning six straight points to claim the victory.
It was Williams' second straight win over Kuznetsova after the Russian won their previous five matchups.
Elsewhere, Lucie Safarova of the Czech Republic defeated a top-10 player for the first time in 24 months, delivering a 7-6 (5), 6-1 victory over fourth-seeded Dominika Cibulkova.
Safarova fought to win a first-set tiebreaker before rolling over the world's No. 4 player from Slovakia in the second set. Her most recent Top 10 win was a victory over Germany's Angelique Kerber at the 2015 BNP Paribas Open at Indian Wells, Calif.
Safarova was hampered by a bacterial infection that affected her playing ability over the past two years.
"It means a lot," Safarova said of the win over Cibulkova. "It feels great to be there again with the best players. Being able to beat them means my level is there again."
Safarova next faces 12th-seeded Caroline Wozniacki of Denmark. Wozniacki defeated sixth-seeded Garbine Muguruza of Spain, winning the first set 7-6 (1) before Muguruza retired due to illness.
"She's playing great tennis again," Safarova said of Wozniacki. "I think it's a little bit similar game to Dominika -- Caroline puts a lot of balls back. I have to be patient but play aggressive and again come up strong and try to go for it. I feel healthy now -- thank God! -- and I'll keep trying to push my limits more and more."
Meanwhile, Kerber, the top seed, advanced with a 6-2, 6-2 win over Japan's Risa Ozaki. The German hit 17 winners while dispatching the qualifier.
"She came through the qualies, she beat good players. I was ready for it," Kerber said after the match. "I talked with my team and I know that she's moving good and bringing a lot of balls back. I was trying to play my game and be aggressive."
Kerber faces either 11th-seeded American Venus Williams or seventh-seeded Russian Svetlana Kuznetsova in the quarterfinals. Williams and Kuznetsova met in Monday's late match.
Second-seeded Karolina Pliskova also was a straight-set winner, beating fellow Czech Republic native Barbora Strycova, the 15th seed, 6-1, 6-4.
Pliskova meets 26th-seeded Mirjana Lucic-Baroni in the quarters. Lucic-Baroni of Croatia defeated American Bethanie Mattek-Sands 7-5, 6-4.
Lucic-Baroni recorded a memorable three-set semifinal victory over Karolina Pliskova earlier this year at the Australian Open.
"It's going to be a really tough match; we both know each other really well," Lucic-Baroni said of the rematch. "I have my game plan and I'm going to try and stick to it and play well tomorrow. We'll see how it's going to look."
Third-seeded Simona Halep of Romania and 10th-seeded Brit Johanna Konta will meet in another quarterfinal.
Halep was a 4-6, 7-5, 6-2 winner over 14th-seeded Australian Samantha Stosur, while Konta notched a 7-5, 6-1 victory over Spain's Lara Arruabarrena.
"I'm happy that I'm still here and get to play another match," Konta said. "I don't necessary believe in 'open fields,' because every single player in this draw is world-class. So every match is as tough as the next."