Kei Nishikori was as surprised as anybody by Naomi Osaka going out of the Tokyo Olympics, but stressed it did not add to pressure on his shoulders.

Japan's two standard-setters in tennis are at opposite ends of their careers, with Nishikori seemingly in a slow decline and Osaka expected to add significantly to her four grand slams.

But the focus on the Japanese public looks set to switch to Nishikori for the rest of the tennis, after he reached the last-16 stage with a 7-6 (7-5) 3-6 6-1 win over American Marcos Giron on Tuesday.

Former world number four Nishikori and Ben McLachlan are through to the doubles quarter-finals too, which may be a likelier route to a medal.

Nishikori already has a bronze to his name from the 2016 Games, where he beat Rafael Nadal in the third-place match.

When asked whether he felt expectations shifting from Osaka on to his shoulders, after she lost to Marketa Vondrousova, Nishikori said: "Not really. I just need to focus on what I have to do on the court.

"It's very sad, of course, that Naomi lost and a surprise. But I knew she had a lot of pressure, this is her first time in the Olympics and I know it's not easy.

"I didn't see her match today, so I cannot say much."

Should Nishikori, now down at 69th in the rankings, beat Ilya Ivashka of Belarus on Wednesday, that could set up a quarter-final against hot favourite Novak Djokovic.


REVENGE FOR VILLAGE FAN TSITSIPAS

It was a weary Stefanos Tsitsipas who was pummelled in the first round of Wimbledon by Frances Tiafoe last month. On Tuesday, a more predictable outcome manifested as Greece's great hope scored a 6-3 6-4 victory over his American opponent.

That loss in London came barely a fortnight after Tsitsipas suffered a heartbreaking loss to Djokovic in the French Open final, from two sets up, and he was succinct with his verdict about what was different this time.

"Concentration and attention levels," was the Tsitsipas assessment.

Next for him is a testing third-round tussle with French shot-maker Ugo Humbert, and Tsitsipas will want to hang around, having been charmed by the Olympic Village experience after so long in the tennis bubble.

"It's a different contrast, it's a different approach completely," Tsitsipas said. "I've made friendships, connected with some other athletes. It's nice to be able to experience something like this. I find the Olympics are really a nice sports event.

"I met a big tennis enthusiast from India. He's doing shooting and we became good friends. I met some of the other Greek athletes, table tennis players, and rowers from different countries."


BRILLIANT BROADY

Liam Broady was a late addition to the Olympics draw and is making the most of the opportunity, with the unheralded British left-hander scoring a terrific 7-5 3-6 6-3 second-round win over Wimbledon semi-finalist Hubert Hurkacz.

Frenchman Jeremy Chardy awaits Broady after beating Russian Olympic Committee's Aslan Karatsev in three sets.

There were also wins on Tuesday for Karatsev's countryman Karen Khachanov and Argentinian Diego Schwartzman, while Wednesday's programme features the entire third-round line-up, including Djokovic's clash with Spain's Alejandro Davidovich Fokina.