NEW YORK, NY, USA - Top seeds Ekaterina Makarova and Elena Vesnina fought off fatigue to defeat Nadiia Kichenok and Anastasia Rodionova, 4-6, 6-2, 6-1 and extend their winning streak to 12 straight matches through the US Open.

Makarova and Vesnina have been the best doubles team for the second straight summer, capturing a third Grand Slam title at Wimbledon and becoming the first team ever to claim the Montréal/Toronto double at the Rogers Cup.

Facing few problems in their first match against Americans Alison Riske and Jennifer Brady, the Russians faced stiffer competition in Kichenok and Rodionova, a new team but one they'd already beaten in Canada two weeks ago.

“I felt a little bit tired on the court, like I had no energy left. All thanks goes to my partner, who carried me through the whole match. It’s not easy to play singles and doubles. It’s a lot of work and you have to do a lot of serving, but I’m really happy that we won today.”

- Elena Vesnina

Vesnina was coming off a heartbreaking late-night singles loss to Madison Keys while Makarova also fell in the third round to Carla Suárez Navarro in three sets, and while both were eager to shake off their respective defeats, Vesnina in particular was feeling the physical effects of the 1:45AM finish earlier that day.

“I felt a little bit tired on the court, like I had no energy left," she told WTA Insider after the match. "All thanks goes to my partner, who carried me through the whole match. At the end of the third set, I just needed some help from the physio to help my back relax a little bit.

"It’s not easy to play singles and doubles. It’s a lot of work and you have to do a lot of serving. I’m really happy that we won today.”

Kichenok and Rodionova showed marked improvement from their Rogers Cup clash, putting pressure on return while holding onto their own serve to stay in front throughout the opening set.

“Nastya Rodionova was so solid, no easy mistakes and making long rallies," Makarova said. "We started so slowly, and I didn’t play as good as I wanted. Elena was slow because of yesterday’s match. We had a lot of chances in the beginning, and didn’t take them."

Playing out on Court 11, the pair regrouped and worked through tense early games to start the second set before earning a crucial break in the fifth game, never looking back.

"We’re helping each other, and it’s easy to talk to one another where, if we’re not feeling something, we can say so and work it out. She understands where to go, and how to help. We’re looking forward to tomorrow."

- Ekaterina Makarova

"I began to understand that I needed to be faster and realize nothing would be easy," Makarova continued. "That’s when we started to fight with our courage on the court, and things worked out from there.”

Makarova and Vesnina have the chance to ascend to WTA Doubles Co-No.1; now that current No.1 Lucie Safarova made the quarterfinals with partner Barbora Strycova, only a title could clinch the elusive spot atop the doubles rankings.

Even at their most tired, the two remained in sync in their post-match interview.

"We will keep it going," Makarova said.

"Match by match," Vesnina added.

"We play tomorrow again. We’re tired from a tough week and tough scheduling, but we love to play doubles…" Makarova trails off.

"…Especially at grand slams," Vesnina picks up before her partner gives the last word.

"We’re helping each other, and it’s easy to talk to one another where, if we’re not feeling something, we can say so and work it out. She understands where to go, and how to help.

"We’re looking forward to tomorrow."

Tomorrow they take on No.14 seeds Andreja Klepac and María José Martínez Sánchez.

Around the grounds...

Makarova and Vesnina wasn't the only top team to endure a tough day at the office. No.4 seeds Sania Mirza and Peng Shuai fought through a third set tie-break against Sorana Cirstea and Sara Sorribes Tormo, ultimately advancing into the last eight, 6-2, 3-6, 7-6(2) on Grandstand.

Safarova and Strycova recovered from a second set hiccup to dispatch Nadiia Kichenok's twin sister Lyudmyla and partner Barbora Krejcikova, 6-1, 5-7, 6-2, and will next face Miami Open champions and No.9 seeds Gabriela Dabrowski and Xu Yi-Fan, who knocked out Shuko Aoyama and Yang Zhaoxuan, 5-7, 6-3, 6-3.

No.2 seeds Martina Hingis and Chan Yung-Jan didn't drop a set on Sunday, but nonetheless were made to fight against No.13 seeds Kristina Mladenovic and Anastasia Pavlyuchenkova before ultimately making it through, 6-4, 7-5. Hingis had an outside shot of returning to No.1 before Safarova and Strycova's win today, bringing the battle down to Safarova and Makarova/Vesnina, who could meet in the semifinals.