The unseeded pairing, which reached the quarter-finals at the Tokyo Olympics, broke serve four times and fired six aces. The Germans will next take on Canadian Denis Shapovalov and Indian Rohan Bopanna for a place in the quarter-finals.
There was another upset Saturday as Fabio Fognini and Lorenzo Sonego, in their second match as a team, defeated the third-seeded pairing of Marcel Granollers and Horacio Zeballos 3-6, 6-3, 10-8. In their only previous match together, the Italians lost in straight sets in the first round at this year’s National Bank Open Presented by Rogers.
Granollers and Zeballos have been in top form as a tandem in 2021, winning three ATP Tour titles, including two ATP Masters 1000 victories in Madrid and Cincinnati. They had won 13 of their past 15 matches prior to this meeting.
In other action, 2021 Hamburg champions Tim Puetz and Michael Venus outlasted the all-Spanish team of Pablo Carreno Busta and Carlos Alcaraz with a 7-5, 6-7(5), 15-13 victory. Puetz/Venus won on their ninth match point, while Carreno Busta and Alcaraz failed to convert any of their six match-point opportunities.
Ivan Dodig and Marcelo Melo also advanced with a 6-7(6), 7-5, 10-2 come-from-behind victory over Cristian Garin and Santiago Gonzalez. The eighth seeds came back from a 2-5 deficit in the second set, winning the next five games and the match tie-break to set up a meeting with Belgians Sander Gille and Joran Vliegen.