The 11^th-seeded pair’s stand-out victory was that over reigning Olympic champions Laura Ludwig and Kira Walkenhorst of Germany, triumphing 21-19, 21-13 in 27 minutes at the Vodny Stadium Beach Sports Centre.

Ross and Sweat started play with a 21-11, 21-12 win over Austria’s Katharina Schutzenhofer and Stefanie Schwaiger in Pool F, bouncing back from a three-set defeat to Canada’s Kristina May and Taylor Pischke yesterday.

They then defeated compatriots Kelly Claes and Sara Hughes 21-16, 21-15 in the first elimination round to earn the match against Ludwig and Walkenhorst.

"It was a long day," said the 31-year old Sweat, who competed at the Rio 2016 Olympic Games with Lauren Fendrick.

"We lost our match yesterday, so we had to get out here early this morning to finish our pool play and this was our third match.

"We have been going back and forth to the hotel, so it has been a busy, long day, but a good day.

"We played solid.

"I don't know if they are dealing with injuries or what, but I am proud of the way we sided out and just were steady at our side."

Next up for Summer and Sweat are Germany’s Karla Borger and Margareta Kozuch, who are seeking to advance to their second FIVB World Tour semi-final this campaign after placing fourth at the season-opening Major Series event in American city Fort Lauderdale in February.

Borger and Kozuch registered elimination-bracket wins today over Russia’s Svetlana Kholomina and Olga Motrich, 21-13, 21-19, and the US’s Fendrick and April Ross, 25-23, 23-21.

Among tomorrow’s other quarter-final matches will be an encounter between Australia’s Louise Bawden and Taliqua Clancy and top seeds Talita Antunes and Larissa Franca of Brazil.

Germany’s Victoria Bieneck and Isabel Schneider face Brazil’s Maria Antonelli and Carolina Salgado, while fourth seeds Agatha Bednarczuk and Eduarda "Duda" Lisboa of Brazil challenge third seeds Chantal Laboureur and Julia Sude of Germany. 

In the men’s competition, two newly-formed Polish teams secured their places in the quarter-finals as 14th-seeded Michal Bryl and Grzegorz Fijalek and 24th-seeded Maciej Rudol and Jakub Szalankiewicz won two matches each today.

Playing in their fourth event this season, Rudol and Szalankiewicz opened play with a 24-22, 21-15 win over Russia’s Ilya Leshukov and Alexander Likholetov.

They then ousted sixth-seeded qualifiers Pedro Solberg and Gustavo "Guto" Carvalhaes of Brazil 21-19, 17-21, 15-12.

"We are very happy," Szalankiewicz said.

"It is the first time ever that I’ve beaten Pedro - he is a good player, so I couldn't be happier.

"I think our serving helped us and we defended a lot of balls.

"Being in the last eight is great as we have to do well here.

"If not, we don't qualify for the World Championships."

Bryl and Fijalek, who are playing in their third event this campaign, beat Latvia’s Martins Plavins and Haralds Regza 21-18, 21-17 and Norway’s Christian Sorum and Anders Mol 21-16, 21-17.

Rudol and Szalankiewicz will meet eighth seeds Viacheslav Krasilnikov and Nikita Liamin of Russia in the last eight, while Bryl and Fijalek will challenge fourth seeds Phil Dalhausser and Nick Lucena of the US.

Arguably the highlight of the quarter-final ties is the meeting between reigning Olympic champions and third seeds Alison Cerutti and Bruno Oscar Schmidt of Brazil and top seeds Aleksandrs Samoilovs and Janis Smedins of Latvia.

Cerutti and Oscar Schmidt were last year’s beaten finalists in Russia’s capital, losing in three sets to The Netherlands’ Reinder Nummerdor and Christiaan Varenhorst.

The other last-eight encounter pits 2015 winners Pablo Herrera and Adrian Gavira of Spain against Russia’s Oleg Stoyanovskiy and Artem Yarzutkin.

The semi-finals are also scheduled to take place tomorrow with the medal matches set to be held on Sunday (June 4).