Canada's Dabrowski, partner Routliffe advance to quarters in U.S. Open women's doubles title defence

Canada's Gabriela Dabrowski and New Zealand's Erin Routliffe continue their quest for a potential repeat at the U.S. Open. The defending women's doubles champions secured a spot in the quarterfinals with a 7-5, 7-6 (3) victory over Italy's Angelica Moratelli and Romania's Jaqueline Cristian on Sunday.

Dabrowski and Routliffe, from Ottawa and New Zealand respectively, clinched the final two games of the second set to force a tiebreaker. They then secured their final three points through forced errors from their opponents. The pair broke serve three times out of eight opportunities and delivered 33 winners.

The top-seeded duo will next compete against either Great Britain's Harriet Dart and France's Diane Parry or Russia's Veronika Kudermetova and Taiwan's Hao-Ching Chan.

In other news, defending champion Coco Gauff was defeated in the fourth round by Emma Navarro in an all-American clash, 6-3, 4-6, 6-3. Gauff struggled with a high number of double-faults—19 in total—compared to just 14 winners.

"I don't want to lose matches like this anymore," Gauff remarked, citing a mix of mechanical and mental issues with her serving.

The No. 3-seeded Gauff, who had won 10 consecutive matches at Flushing Meadows, including her first Grand Slam title last year, was unable to complete a comeback despite a strong mid-match performance where she won 14 of 17 points to take the second set and start the third set positively.

After each of her last two matches in New York, Gauff returned to practice courts to work on her serve, but this did not yield improvements on Sunday, as she had three double-faults in each of three games—two of which she lost. Eleven of her double-faults occurred in the final set.

Gauff also committed a total of 60 unforced errors, with 29 coming from her forehand. Navarro, who had previously defeated Gauff in the fourth round at Wimbledon, finished with 35 unforced errors.

Navarro, who admitted to having a "lull" but managed to regroup for the third set, will next face No. 26 Paula Badosa, who won 6-1, 6-2 against Wang Yafan.

In another women's quarterfinal, No. 2 Aryna Sabalenka, last year's runner-up to Gauff, will play No. 7 Zheng Qinwen, who overcame No. 24 Donna Vekic in the longest women's match in U.S. Open history, finishing at 2:15 a.m. ET after 2 hours and 50 minutes.

Earlier on Sunday, No. 9 men's seed Grigor Dimitrov, with 23-time Grand Slam champion Serena Williams watching and giving a thumbs-up, defeated Andrey Rublev 6-3, 7-6 (3), 1-6, 3-6, 6-3 to advance to the quarterfinals. Rublev, known for his volatile reactions, sought medical attention for a hand injury after hitting it against his racket and displayed frustration by slapping himself during the second-set tiebreaker.

Dimitrov will now face No. 20 Frances Tiafoe, who won against No. 28 Alexei Popyrin, the player who upset Djokovic on Friday.

Also advancing on Saturday was No. 12 Taylor Fritz, who triumphed over three-time Grand Slam finalist Casper Ruud 3-6, 6-4, 6-3, 6-2. Fritz's quarterfinal opponent will be Alexander Zverev, the 2020 U.S. Open runner-up, who defeated Brandon Nakashima 3-6, 6-1, 6-2, 6-2.

"I'm pleased to make the quarterfinals, but I want to push further," Fritz said, reflecting on his desire to advance beyond his current stage in the tournament.