Mizutani, a singles bronze and teams silver medallist at last year's Olympic Games in Rio de Janeiro, is generally considered the best non-Chinese player in the world and was thought to be the one with the best chance of upsetting the world's leading team this week.

The 27-year-old produced a sluggish performance, though, and was constantly forced back from the table against an opponent displaying relentless attacking skill.

Harimoto, the world junior champion and a finallist at the Indian Open in February, produced a brutal display of power, pace and consistency.

He moved 3-0 ahead and conceded a 7-4 lead in the fourth before sealing the fifth for a 4-1 win.

It was all the more impressive considering that the teenager had no coach offering advice in the corner because he was playing a team-mate.

He also had a reputation for playing poorly against other Japanese opponents.

"Age has nothing to do with table tennis," said Harimoto.

"I just wanted to play the game my way. 

"I just wanted to attack and I did this right from the beginning."

Mizutani's exit will come as a boost to Chinese third seed Xu Xin, who lost to him in the team final at Rio 2016 and is in the same quarter of the draw. 

Chinese head coach Liu Guoliang has said that Xu will no longer be considered among the top four players in the Chinese team if he does not perform well this week.

He showed no sign of nerves today in a 4-0 success over Wang Zengyi of Poland.

Top seed and defending champion Ma Long was made to work hard in a 4-2 win over Anton Kallberg of Sweden.

Second seed Fan Zhendong beat another Swede in Par Gerell, 4-0.

Olympic silver medallist and fourth seed Zhang Jike, the world champion in 2011 and 2013, defeated Robert Gardos of Austria 4-2.

Earlier, Fan and Xu ended the hopes of Chinese-German pairing Ma Long and Timo Boll with a 4-1 win in the doubles third round. 

Hungary's Tamas Lakatos was another shock singles winner today as the qualifier, ranked 191st in the world, beat 21st seed and Olympic team bronze medallist Bastian Steger of Germany to reach the last 32.

Romania's Elizabeta Samara created one of the biggest upsets in the women's singles third round as she battled to a superb 4-3 win over ninth seed Hitomi Sato of Japan.

The world number 31, who had knee surgery earlier this year, initially trailed 0-2 against an opponent with a fiddly defensive style before a superb recovery.

Asian champion Miu Hirano fared better than her team-mate in progressing comfortably into the last 16 with a 4-1 win over Chen Szu-yu of Taiwan.

World number one and defending champion Ding Ning also won easily 4-0 over Ni Xia Lian of Luxembourg.

Ding will join four Chinese team-mates in the fourth round after all five won in straight sets.

Second seed Liu Shiwen beat South Korea's Suh Hyo-won, third ranked Zhu Yuling dominated Kim Kyung-ah, fifth seed Meng Chen beat Dana Cechova of Czech Republic and unseeded Mu Zi overcame Li Qian of Poland.

Fourth seed Feng Tianwei of Singapore was made to work hard in a 4-2 win over Hong Kong's Lee Ho-ching.

A German medal is guaranteed in the mixed doubles after Petrissa Solja and Chinese partner Fang Bo qualified for the semi-finals.

The pair have improved through the tournament and beat Sweden's Mattias Karlsson and Matilda Ekholm 4-1 today.

Maharu Yoshimura and Kasumi Ishikawa of Japan now lie in wait after they beat South Korea's Lee Sang-su and Yang Haeun 4-1 in their quarter-final.

Chen Chien-an and Cheng I-ching of Taiwan eased through in the bottom half of the draw 4-0 over Spain's Alvaro Robles and Galia Dvorak to set up a last-four clash with Wong Chun-ting and Doo Hoi-kem of Hong Kong.

Wong and Doo inflicted the first Chinese defeat of the week this morning after edging Feng Yalan and Danish partner Jonathan Groth 4-3 before a 4-2 quarter-final win later in the day over Kenta Tazoe and Miyu Maeda of Japan.

Mixed doubles semi-finals and finals are scheduled for Saturday (June 3).