John Millman will be the first man to try to stop Alexander Zverev claiming back-to-back titles in Cologne, while Jannik Sinner also won.
Andy Murray entered the ATP 250 tournament in Cologne to build up match practice, but he tumbled out in the first round on Tuesday.
Fernando Verdasco fell to a third consecutive loss with an early exit at the Rio Open.
After a solid start to 2020, Fernando Verdasco suffered a surprise loss in the Cordoba Open first round.
Daniil Medvedev had not lost since the US Open final before Jeremy Chardy brought him back down to earth in Paris.
Fernando Verdasco had won all four matches against Dominic Thiem but his dominance of the Austrian ended in Vienna on Thursday.
Fernando Verdasco was unable to continue Taylor Fritz's run of first-round exits as the American advanced in three sets.
Richard Gasquet lost for just the second time in nine career meetings with Benoit Paire in an-all French clash in Metz.
Inspired by Naomi Osaka's solidarity with Coco Gauff at the US Open, we look at some of the greatest moments of sportsmanship.
World number four Dominic Thiem has never won his home tournament but moved into the semi-finals with a hard-fought win over Pablo Andujar.