Friday 20 February 2015 15:35, UK
Yoshihito Nishioka has become the first teenage qualifier to reach the Delray Beach Open quarter-finals since Kei Nishikori.
Nishioka defeated Australia's Marinko Matosevic 6-1 6-3 as he looks to emulate the feat Nishikori managed in 2008, when he went on to win the title as an 18-year-old.
He has already followed Nishikori's lead in moving from Japan to the IMG Tennis Academy in Bradenton, Florida, courtesy of the Morita Fund, a scholarship designed to develop Japanese talent.
Nishioka powered through the opening set only to concede a break in the first game of the second but a Matosevic double fault allowed him to break back, and Nishioka broke serve again to go 5-3 up by forcing an error from the Australian.
The 19-year-old will now face Bernard Tomic in the next round after Tomic eliminated his doubles partner Viktor Troicki in a marathon lasting nearly two hours in searing heat.
He won 6-3 6-7 6-4 to reach his fourth quarter-final of the season.
Donald Young is also through to the last eight after a 6-3 6-2 win over Alejandro Gonzalez.
"I needed to know why I was losing and my peers were doing better," said Young about the sports psychologist that improved his fortunes.
"She taught me to focus on the ball and things that I can control. I can just control my mind, what I do on my serve, my competing and my effort."
Young will play Alexandr Dolgopolov next after the Ukrainian defeated Tim Smyczek 6-2 6-4.
