The 10th seeds started the day at the four-star event with a 21-17, 22-20 victory over Germany’s Victoria Bieneck and Isabel Schneider and then faced compatriots Kelley Larsen and Emily Stockman, the seventh seeds, in the Pool G decider at the Luzhniki Olympic Complex.

They were taken to three sets in that match, but Walsh Jennings and Sweat ultimately prevailed 21-19, 14-21, 15-10 to ensure they will advance straight through to the second knock-out round.

"I really love Moscow," Walsh Jennings said.

"I think it’s the most beautiful city in the whole world. 

"I am so happy to be here playing on my birthday. 

"The only thing missing is my family. 

"We had two wins today against two good teams, but my wish has not come true yet. 

"I can’t tell you what it is. 

"When I make it come true, I‘ll tell you."

Among the other women’s table toppers were 16th-seeded Italians Marta Menegatti and Viktoria Orsi Toth in Pool A, second-seeded Brazilians Agatha Bednarczuk and Eduarda Santos Lisboa in Pool B, 19th-seeded Czechs Barbora Hermannová and Marketa Slukova in Pool C, and fourth-seeded Brazilians Ana Patricia Silva Ramos and Rebecca Cavalcanti Barbosa Silva in Pool D.

Completing the list were Japanese wild cards Megumi Murakami and Miki Koshikawa in Pool E, sixth-seeded Americans Kelly Claes and Sarah Sponcil in Pool F, and eighth-seeded Russians Ekaterina Birlova and Evgenia Ukolova in Pool H.

In the men's event, Brazilian wild cards Gustavo Albrecht Carvalhaes and Saymon Barbosa Santos, who advanced to the main draw from yesterday's qualifications, continued their winning streak by snatching two come-from-behind tie-breaker victories to finish at the summit of Pool D and progress directly to the round of 16, along with seven other pairs.

Guto and Saymon, seeded 20th in the main draw, opened with a 17-21, 21-16, 15-13 win against experienced Spaniards Pablo Herrera Allepuz and Adrián Gavira Collado.

They then went onto beat fourth-seeded Dutchmen Alexander Brouwer and Robert Meeuwsen 17-21, 21-18, 15-9 in the Pool D decider.

The other duos progressing directly to the round of 16 included first-seeded home favourites Viacheslav Krasilnikov and Oleg Stoyanovskiy from Pool A, second-seeded Brazilians Alison Cerutti and Alvaro Morais Filho from Pool B, and 30th-seeded Poles Maciej Rudol and Jakub Szalankiewicz from Pool C. 

They were joined by 12th-seeded Russians Nikita Liamin and Taras Myskiv from Pool E, 11th-seeded Americans Jacob Gibb and Taylor Crabb from Pool F, 23rd-seeded Belgians Dries Koekelkoren and Tom van Walle from Pool G, and ninth-seeded Russians Konstantin Semenov and Ilya Leshukov from Pool H.

Action in Moscow is due to continue tomorrow.