Third-seeded Jessica Pegula converted seven of 10 break points while notching a 6-1, 7-5 victory over Magda Linette on Monday to reach the quarterfinals of the Miami Open.
Pegula won 72 percent of her first-serve points compared to 54.5 percent for Linette to advance to play Russian Anastasia Potopova in the quarters.
"Everything was working, and then in the second set things got tough," Pegula told the Tennis Channel. "I felt like I was going for too much at times. But I'm glad I was able to get some energy there and finish in two."
Linette, from Poland, is a close friend of Pegula and the two often train together in nearby Boca Raton. Both players had four aces.
Pegula and the 27th-seeded Potapova played earlier this month at Indian Wells when Pegula rallied from a set down to post a three-set victory. Potapova is looking forward to another opportunity.
"I was pretty close to getting this win, but she was better that day," Potapova said of the recent matchup. "I worked on some things since then, and I really hope it's going to work."
Potapova earned another chance with her 6-4, 7-6 (4) win over China's Qinwen Zheng on Monday. Zheng, the 23rd seed, had nine aces to Potapova's one.
Also moving on was Indian Wells champ Elena Rybakina, the No. 10 seed from Kazakhstan. Rybakina drilled 10 aces during a 6-4, 6-3 victory over Elise Mertens of Belgium to run her winning streak to 11 consecutive matches.
"I'm happy the day was two sets but it was a really tough one," Rybakina told the Tennis Channel. "Elise played really well. It was not easy. I had so many chances."
Rybakina next plays 25th-seeded Martina Trevisan after the Italian recorded a 6-3, 6-3 win over 24th-seeded Jelena Ostapenko of Latvia.
No. 15 seed Petra Kvitova of the Czech Republic engineered a strong second-set rally to post a 7-5, 7-6 (5) victory over Varvara Gracheva of Russia. Gracheva held a 5-2 lead in the second set before Kvitova won four of the next five games to force a tiebreak and then Kvitova jumped out to a 5-1 lead in the breaker before sealing the win.
Also, Romania's Sorana Cirstea moved on with a 7-6 (3), 6-4 victory over Czech Marketa Vondrousova.
--Field Level Media