Fourth-seeded Jessica Pegula is making another deep run at the U.S. Open and she claimed her spot in the quarterfinals Sunday with an easy 6-1, 6-2 victory over fellow American Ann Li in New York. Pegula converted 6 of 9 break points and needed just 54 minutes to subdue Li, who committed 19 unforced errors while playing in Arthur Ashe Stadium for the first time. Pegula next will face two-time Grand Slam winner Barbora Krejcikova of the Czech Republic. Krejcikova staved off eight match points while rallying to a 1-6, 7-6 (13), 6-3 victory over upstart Taylor Townsend. Krejcikova held a 43-37 edge in winners while needing three hours and four minutes to finish off Townsend, who was vying to reach the quarterfinals of a Grand Slam event for the first time. Townsend dominated the first set and had a chance to close the deal in straight sets. She was leading 6-3 in a second-set tiebreaker before letting three straight match points get away. The two women traded big hits and missed shots throughout the 25-minute tiebreaker before Krejcikova finished off the 98-minute set with a slam. Seven of Townsend's squandered match points came in the second-set tiebreaker. Krejcikova broke Townsend's service to make it 4-2 and 5-3 in the third set before finishing off a scintillating victory that disappointed the pro-American crowd at Louis Armstrong Stadium. "I'm totally enjoying this crowd. Even though it's not for me, it's fine," Krejcikova said in her on-court interview. "I love the atmosphere. I love when they're cheering. They're making the match huge. It's for the Americans. It's not for me. "I wish we had a tournament in Czech Republic and there were a lot of fans rooting for me. Maybe in a different life. Not now. I'm just enjoying. I'm having fun on court. I'm so happy I can be here. It's a huge privilege that I can play in front of such a nice crowd on Armstrong." Krejcikova's impressive showing snuffed out the dreams of the 29-year-old Townsend, a No. 1 doubles player who is enjoying the top singles run of her career. "It just stings because I literally gave everything," Townsend said. "She came up with some really, really great tennis in moments where she was down, and I thought I had it." Townsend lost in the first round of the other three majors this year before winning her first three matches at the Billie Jean King Center. She swept No. 5 seed Mirra Andreeva of Russia on Friday, two days after beating No. 25 Jelena Ostapenko of Latvia in straight sets and being on the receiving end of some disparaging comments about her lack of sportsmanship. Pegula, a 2024 finalist, is more used to being on the big stage in New York. "I've obviously kind of earned that right over the years," the 31-year-old Pegula said of playing in Ashe. "When I was younger, I never hit on Ashe, I never played on Ashe. I was always on another court, Court 17 or maybe Grandstand if I was lucky. That's definitely changed. "Specifically here being an American, I have played a lot there now. Maybe against someone that hasn't gotten a lot of reps on that court, I think it is a little bit like a home-court advantage." This marks the third time Pegula has advanced to at least the quarterfinals of the U.S. Open. She lost to Aryna Sabalenka of Belarus in last season's title match and also reached the quarters in 2022. Pegula has won just one of three matchups against Krejcikova. Pegula's victory came in the 2023 Australian Open round of 16. On Sunday, Pegula outclassed the 25-year-old Li and was highly effective at the net by winning 12 of 15 points. "It's a part of my game I can use as a weapon," Pegula said. "We've definitely worked on that a lot. They're really happy when I can finish a point with an overhead or a volley at the net." Pegula won the first three games of the match while sailing through the first set. It was more of the same in the second as she won four of the first five games before finishing off the match. Later Sunday, top seed Aryna Sabalenka of Belarus cruised past Spain's Cristina Bucsa 6-1, 6-4, posting more winners (26-9) and never having to save a break point. She advanced to the quarterfinals without dropping a set and will remain the top-ranked player after the tournament. The Czech Republic's Marketa Vondrousova knocked off ninth-seeded Elena Rybakina of Russia 6-4, 5-7, 6-2 in one hour, 51 minutes. Vondrousova, the 2023 Wimbledon winner, had the edge in aces (13-5) and won 5 of 7 break-point opportunities, to 3 of 6 for Rybakina, the 2022 Wimbledon champion who had more winners (40-29) and unforced errors (38-15). --Field Level Media