Swiss sixth seed Patty Schnyder suffered a first round defeat in front of her home fans at the Zurich Open on Tuesday, losing 6-4, 3-6, 6-4 to Czech qualifier Petra Kvitova.
Schnyder had been hoping to win her second Zurich title following her 2002 tournament triumph, but threw away a 3-0 lead in the third set to let her teenage opponent take control.
"Of course I'm disappointed but I can't make any excuses," the 29-year-old said following her defeat by the world number 57.
"It was a strange match with an unhappy ending. She recovered (from trailing 3-0) and hit a lot of winners. I couldn't find a way to make it difficult for her after that."
Russian seventh seed Anna Chakvetadze was another casualty on Tuesday, going down 3-6, 6-3, 6-2 to Romanian world number 66 Monica Niculescu.
With the tournament's top four seeds all receiving byes into the second round, Polish world number 10 Agnieszka Radwanska was the highest seed in action and eased past Russian qualifier Vera Dushevina 6-4 6-1.