Yibing Wu put his best foot forward in the Boss Open on Tuesday with a 7-5, 6-3 first-round victory over Nick Kyrgios, who was playing in his first match since undergoing knee surgery in January.

Wu, of China, withstood 15 aces from Kyrgios, who was struggling physically and told his team he was unable to “walk without pain.” Wu advanced to the second round of the tournament in Stuttgart, Germany.

Also, Aslan Karatsev of Russia needed three hours and 12 minutes to dispatch Frenchman Corentin Moutet, 7-6 (0), 6-7 (8), 7-5.

Other first-round winners included Jan-Lennard Struff of Germany, Gregoire Barrere of France, Christopher O’Connell of Australia, Marton Fucsovics of Hungary and Tommy Paul.

Libema Open

Sixth-seeded Tallon Griekspoor of the Netherlands defeated Sweden’s Mikael Ymer 6-2, 3-6, 6-3 in the first round at ‘s-Hertogenbosch, Netherlands.

Aussies Jordan Thompson and Alexei Popyrin also advanced with wins.

Alexander Bublik of Kazakhstan’s advanced with a straight-sets win over Belgium’s David Goffin, and Mackenzie McDonald also moved on in straight sets.

Other winners included Emil Ruusuvuori of Finland, Adrian Mannarino of France and Laslo Djere of Serbia.

–Field Level Media