Stefanos Tsitsipas is taking inspiration from the grandfather he has never met after battling through to round two of the men's singles at Tokyo 2020.

Alexander Zverev had an altogether more comfortable progression at Ariake Tennis Park, while home favourite Kei Nishikori earned an impressive upset win.

Felix Auger-Aliassime was unable to make the most of two-time defending champion Andy Murray's withdrawal, but it was a good day for Hubert Hurkacz. 

Here's the pick of the action from day two of the men's singles.

TSITSIPAS OUT TO EMULATE GRANDFATHER

Greek ace Tsitsipas, a French Open finalist this year, had to dig deep for a three-set win over Philipp Kohlschreiber.

Should he manage to win gold in the Japanese capital he would be matching the feat of his grandfather, who won the football competition representing the Soviet Union in 1956.

"I've never had the opportunity to meet him. But my mom told me stories of his career and how he got it," he said. "He kind of inspires me in a way. I know what kind of athlete he was, with all the achievements and all the trophies. I'm proud of him. 

"It's something good, a legacy that is being carried on in the family. I'm happy to be the next in the family to be competing at the Olympics."

ZVEREV LOVING OLYMPICS EXPERIENCE

Fourth seed Zverev coasted past Lu Yen-hsun 6-1 6-3 and spoke of how much he is enjoying being around other German athletes.

"Normally you don't have those guys around that much, you have your friends, of course you have people that are around you, but you don't sleep in the same room as them," he said.

"Yes it is very different but in a way very enjoyable. The Olympics are once every four years, and it’s five years now, so I think everybody is enjoying it and everyone is having the best time that they can."

Nishikori is playing at a fourth Olympics and upset fifth seed Andrey Rublev 6-3 6-4. For the 31-year-old the motivation is simple.

"It's [playing in Japan] something I always dreamed of when I was little," he said. 

"Especially now, with the Covid situation, if I can win as many as I can, I think it will bring better news, that's something I'm trying to do this week."

AUGER-ALIASSIME FAILS TO MAKE MOST OF MURRAY ABSENCE

Auger-Aliassime was scheduled to face Murray before the Team GB star pulled out with a quad issue and will instead focus on doubles.

The Canadian was felled by Murray's replacement Max Purcell, though, the Australian winning 6-4 7-6 (7-2).

Fellow seed Gael Monfils also crashed out but Hurkacz was a 6-2 6-4 victor over Luke Saville, while Diego Schwartzman also made it through.