Career
Junior career
Junior Grand Slam singles results:
Australian Open: 3R (2013)
French Open: 2R (2012, 2013 )
Wimbledon: 2R (2012, 2013)
United States Open: San Francisco (2012)
2014
Nishioka qualified for the United States Open in his first Grand Slam qualifying appearance, but he was forced to retire in the first round match against Paolo Lorenzi because of illness. The Next week, he claimed his first Association of Tennis Professionals Challenger Tour title in Shanghai by beating Somdev Devvarman in the final. In September, Nishioka earned men"s singles gold medal in the 2014 Asian Games at Incheon, where he upset top seed Lu Yen-hsun of Chinese Taipei in the final.
2015
Nishioka qualified for the Delray Beach Open in February.
He lost to Bernard Tomic in straight sets. During spring clay court season, Nishioka made his debut at the 2015 French Open, losing to fourth seed Tomas Berdych in first round.
In the 2015 United States Open, Nishioka advanced to the second round of Major for the first time in his career, beating fellow qualifier Paul-Henri Mathieu in five sets. He was beaten by 30th seed Thomaz Bellucci in next round.
In November, he ended 2015 season with his second challenger title in Toyoya, beating Alexander Kudryavtsev in the final.
2016
By winning the Asia-Pacific wildcard play-offs in Shenzhen, Nishioka earned a wildcard into the 2016 Australian Open. However, he fell in the first rounds to Pablo Cuevas. In February, he reached the quarterfinal of the Memphis Open as a qualifier, winning over Jared Donaldson and Illya Marchenko along the way.
He lost to fourth seed Sam Querrey in straight sets.
Nishioka qualified for the Miami Open to make his Association of Tennis Professionals World Tour Masters 1000 main draw debut, getting to the third round after beating fellow qualifier Jared Donaldson and 21st seed Feliciano López. He lost his chance to compete in the round of sixteen when he was beaten by 14th seed Dominic Thiem. finals
Singles: 2 (2 titles)
Doubles: 1 (1 runner-up).