CHARLESTON, S.C. (AP) — Not the windy conditions nor the sight of good friend Daria Gavrilova on the other side of the net could deter Daria Kasatkina.
In a three-set duel between the Russians that lasted well over two hours on Thursday, Kasatkina beat Gavrilova 6-3, 4-6, 6-0 to reach her second straight quarterfinal at the Volvo Car Open.
Kasatkina won 14 of 19 break points while Gavrilova converted just 2 of 10.
"It was very difficult, and I was playing against my very good friend, so it was like double portion of toughness," Kasatkina said. "The main key was, I think, the break points. I won almost every break point."
A powwow with her coach mid-match didn't hurt.
"He told me I was start (ing) to play quite soft, and I stopped moving," Kasatkina said. "He was right because in the third set I pushed myself to play more aggressive, to start to move with the legs, and I did the job."
Up next for Kasatkina is No.10 seed Irina-Camelia Begu, another 2016 quarterfinalist who stunned 2010 champion Samantha Stosur to start the day in Charleston.
"I came here with not a lot of expectations for sure," Kasatkina said. "I was just happy that I came back on the clay so I can play my favorite tennis, and I'm happy that I'm moving on. I had a few tough months (last year). I couldn't win a match."
Begu will play in the quarterfinals for the third time in her career after her 7-5, 6-3 victory over Stosur. The Romanian, who's reached the round of eight in each of her three career appearances in Charleston, ran off five straight games from 4-5 down in the first set and never faced a break point in the second, taking the victory in 1 hour, 39 minutes. And she stayed composed in the wind, connecting on 21 winners to just 13 unforced errors as her Australian rival struggled to find any sort of rhythm, hitting 24 unforced errors with 15 winners.
Also advancing was Caroline Wozniacki of Denmark, who defeated Germany's Annika Beck 7-5, 6-1 in a second-round match held over from Wednesday night due to weather. The fifth-seeded Wozniacki, who lost to Johanna Konta of Britain in the final of the Miami Open last Saturday, saved four of five break points in the decisive second set while Beck failed to save any in three tries.
In other singles matches on the green clay at Daniel Island: Anastasija Sevastova of Latvia defeated Ons Jabeur of Tunisia 7-5, 7-6 (6); Mirjana Lucic-Baroni of Croatia upset seventh-seeded Kiki Bertens of the Netherlands 7-6 (5), 6-4; Laura Siegemund of Germany defeated Lucie Safarova of the Czech Republic 6-2, 6-3; and Jelena Ostapenko of Latvia defeated Fanny Stollar 6-1, 1-0 after the Hungarian teenager retired.
In doubles competition, Abigail Spears of the United States and Katarina Srebotnik of Slovenia defeated Kateryna Bondarenko of Ukraine and Canadian Gabriela Dabrowski 6-1, 6-4.