Defending men's champion Artem Sitak has suffered shock quarterfinal defeat at the New Zealand Tennis Championships in Auckland.
Second seed Sitak has been beaten by 17-year-old Aucklander Macsen Sisam, a promising junior who has claimed the biggest scalp of his young career.
The sixth seeded Sisam is through to the semifinals after a 7-5 6-4 victory over the ATP Tour doubles specialist.
Tennis New Zealand high performance manager Simon Rea said Sisam displayed an aggressive mind-set throughout and deserved his win.
"He never wavered in his approach and stayed on top of the point and it's a top result for him."
The men's and women's quarterfinals were continuing at the Albany Tennis Centre on Thursday afternoon, with the semifinals and finals to be staged at the ASB Tennis Arena on Friday and Saturday.
The singles winners receive wildcards into ASB Classic qualifying.