Australian Bernard Tomic continued his pre-Wimbledon build-up on grass, overpowering Tommy Haas 7-6 (8/6), 6-2 on Thursday to reach the quarter-finals in Stuttgart.
The fifth-seeded Tomic from Queensland cut short the comeback week of the 37-year-old Haas, who was playing for the first time in more than a year since undergoing shoulder surgery.
Tomic had to battle to close out victory, with former ATP number two Haas salvaging three match points in the penultimate game on the new grass of the Weissenhof club, which was changed from clay in time for this edition.
Tomic concluded victory with a love game to advance to the last eight in just over an hour and a quarter.
The 22-year-old winner broke twice with Haas saving six other break points as the wild card-entry veteran worked his way back into the sport after yet another lengthy injury pause.
Tomic’s win gave him bragging rights in Germany after losing to Haas three years ago on grass in Halle when the Aussie retired in the first set due to an abdominal injury.
Tomic will next take on the winner from top seed Rafael Nadal and Marcos Baghdatis.
Mischa Zverev assured at least one local in the quarters as he defeated Italian Andreas Seppi 6-2, 6-4.
Zverev, ranked 502, will be playing in his first quarter-final since Halle in 2013 when he lost to Roger Federer.