Former French Open champion Anastasia Myskina slumped to a 6-4, 4-6, 6-4 first round defeat by Polish 17-year-old Agnieszka Radwanska at the Warsaw Cup on Tuesday.
Radwanska, winner of the 2005 Wimbledon junior title, troubled Myskina with a strong forehand and often caught her out with beautifully executed drop shots on the clay surface.
She grew in confidence and held her nerve in the finale against Myskina, who rarely looked comfortable.
"Obviously this was a very big surprise for me because Myskina is one of the best players in the world," said 309th-ranked Radwanska. "I wasn't expecting this victory at all and I'm just very very happy I was able to win here."
"It's my first tournament on clay and the girl was playing pretty good," Myskina told reporters. "Just a couple of mistakes and the match is over. I saw her for the first time in my life so it's a little bit difficult to play her."
Myskina opened by breaking Radwanska for 2-0 but then hooked a backhand long from a return which allowed Radwanska to break back in the fifth game.
Another backhand error gave the Pole a second break for 5-4, and she closed out the set in the next game.
Coming back from a break in the second set Myskina managed to take the match into a decider, but Radwanska retained her composure and a perfectly executed backhand down the line gave her a double break to lead 3-0.
Both players dropped their serve to love in the next two games after which Myskina broke to trail 4-2.
In the final game, Radwanska held off a break point with a forehand winner into the corner, and then closed out the match with another winning forehand.