Yoshihito Nishioka secured a dream result on Wednesday as he defeated longtime idol and Japanese countryman Kei Nishikori 7-6 (7/2), 6-4 at the ATP Cincinnati Masters.
Sixth-seeded Nishikori, Asia's top-ranked player, went down to his 77th-ranked compatriot, who came through qualifying, in just over 90 minutes.
For the winner, the second-round success was legendary.
"I was so excited to play with him, because he's the hero of the Japanese tennis, Asian tennis," Nishioka said.
"I couldn't sleep yesterday, I know him very well. I was watching him when I was junior. I was learning many things from him.
"I tried to go his weakness, I just wanted to be my best against my hero.
"This was a very important experience for me. Today I learned many things from him. The most important thing was to play with him."
Nishikori, a 2014 US Open finalist, has never been past the third round in Cincinnati while Nishioka is making his first appearance.
Nishioka will aim for the quarter-finals on Thursday against Australian Alex di Minaur.
Divided loyalties: A fan holds up a sign during the Yoshihito Nishioka against Kei Nishikori match