World number three Alexander Zverev advanced to the final eight of the Halle Open grass-court tournament on Thursday, continuing his winning run since his French Open victory on clay earlier in June.
Welcomed by a supportive crowd, top seed Zverev beat Yannick Hanfmann 6-3, 7-6 (7/4) in an all-German duel to keep his hopes alive of a first grass court title in his career.
Zverev broke Hanfmann once to take the opening set. In the second, both players held firm on their own serve to force a tie break, which Zverev won comfortably.
The top seed said he was still adjusting from clay, his preferred surface, to grass, saying he wanted to improve his return, which "is the most important shot on grass".
"I've only been on a grass court for a couple of days but I'm through to the quarter-finals, so I'm happy with that," Zverev added.
The 29-year-old beat Italy's Flavio Cobolli in a seesawing five-set Roland Garros showpiece to break through for a first ever Grand Slam title.
The former Olympic gold medallist had come agonisingly close but had never broken through, losing three Grand Slam finals.
On Wednesday, Cobolli got a modicum of revenge for the Roland Garros defeat by eliminating Zverev in the doubles on the Halle grass.
Zverev, who made the final at the Wimbledon warm-up tournament in 2016 and 2017, will face Belgian Raphael Collignon on Friday for a place in the semi-finals.
Earlier on Thursday, world number five Ben Shelton beat fellow American Ethan Quinn 6-4, 5-7, 6-4 to set up a quarter-final meeting with Taylor Fritz, who he beat in the final of Sunday's ATP event in Stuttgart.
In the other quarterfinals, Canadian world number four Felix Auger Aliassime will face American Frances Tiafoe while 2021 US Open champion Daniil Medvedev takes on German Daniel Altmaier.