The duo were initially knocked out by Brazil’s Gabriel Heilborn Gouveia and Rafael Jose Mendonca de Queiroz in round three of the qualification tournament, before they found themselves back in the competition at a purpose-built stadium in Tangshan with the lucky loser ticket.

Despite losing their opening Pool A match yesterday to China’s Chuanyong Liu and Tingyang Yan, Kindl and Klaffinger begun play today with a 21-18, 21-15 win over Costa Rica’s Nicolas Velluti Morales and Fabian Guerra Esquivel.

They then overcame the United States’ Clay Messenger and Adam Wienckowski, triumphing 21-14, 21-18.

"We had nothing to lose because actually we lost in the qualification so we had an empty mind and we could play freely, without pressure," Klaffinger said.

The Austrians finished first in Pool A on point difference above Liu and Yan and Messenger and Wienckowski, both of whom picked up two wins and are also through to the knock-out phase.

Pairing up for the first time, Brazil’s Adrielson Dos Santos Silva and Renato Andrew Lima de Carvalho are another duo showing good form in Nanjing and have topped Pool B with three straight-set wins.

Today, they followed up a 21-9, 21-14 victory over Mozambique’s Ronaldo Andela and José Alberto Mondlane by overcoming Argentina’s Mauro Zelayeta and Bautista Amieva 21-18, 21-15.

Zelayeta and Amieva have also proceeded out of pool play and into the knock-out phase after finishing third behind Italy’s Paolo Cappio and Jakob Windisch.

The eight pool winners advance directly to the round of 16, while the second and third-place finishers will face off in the round of 24.

The other teams to register three pool wins and enter directly into the round of 16 are Brazil’s Gouveia and Jose Mendonca de Queiroz, Switzerland’s Florian Breer and Yves Haussener, Poland’s Mateusz Paszkowski and Maciej Lewicki, Latvia’s Kristaps Smits and Mihails Samoilovs, and Germany’s Julius Thole and Lukas Pfretzschner.

In the women’s event, Russia’s Nadezda Makroguzova and Svetlana Kholomina moved one step closer to a second Under-21 World Championship podium.

The duo, who claimed silver at last year’s event in Swiss city Lucerne, beat Poland’s Martyna Kloda and Kinga Legieta 21-19, 21-14 in a Pool C decider.

It means they remain undefeated after three matches without dropping a set.

Lucky losers Natalie Honzovicova and Tereza Pluharova secured their progression from Pool A as runners-up after the Czechs defeated Thailand’s Pawarun Chanthawichai and Thatsarida Singchuea, the 2017 Under-21 Asian Championship winners, 21-9, 21-11.

China’s Wang Jiaxi and Wang Jing took first spot, while Pawarun and Thatsarida also qualified as the third-place finishers.

Among the teams with three pool wins in Nanjing, topping their respective pools, were defending champions Eduarda Santos Lisboa and Ana Patricia Silva Ramos of Brazil.

Others included last year’s bronze medallists Megan and Nicole McNamara of Canada, the US’s Kathryn Plummer and Milica Mirkovic, Paraguay’s Michelle Sharon Valiente Amarilla and Giuliana Poletti, Latvia’s Tina Graudina and Anastasija Kravcenoka, and Belarus’ Viktoryia Shalayeuskaya and Viktoryia Siakretava.

The quarter-final line-ups in both the men’s and women’s competitions are due to be determined by the end of play tomorrow.