World junior number one Victoria Azarenka of Belarus upset American Amy Frazier 6-2 5-7 6-4 at the ASB Classic in Auckland on Monday.
Frazier was last year's top seed and was expected to win her first round match on court four at the ASB Tennis Centre but found the work hard going from the first point.
Azarenka claimed the first set without too much difficulty 6-2, using her powerful baseline play to good effect in the process.
Frazier came back with typical patience and her solid style of play to win the second set 7-5.
It appeared that Azarenka might struggle in the decider given her opponent's experience - Frazier was playing on the WTA tour before she was even born but the 16-year-old showed tremendous composure and played out a 6-4 deciding set win.
"I found it very good," Azarenka said after the match.
"I didn't think Amy played that well at the beginning - she wasn't really into her rhythm. But then she started playing very well.
"It was very close and a very good match and I think everyone enjoyed it."
The Belarusian is ranked 170th in the world and used one of four wild cards she is allowed in 2006 to make it into this tournament.
The idea behind using one up now is that if she can earn enough tour points early in the year, she can then make other tournaments on merit.
Azarenka is scheduled to meet the winner of Tuesday's match between Russian fourth seed Maria Kirilenko and Czech Olga Blahotova.
