Champion Venus Williams was unceremoniously dumped out of the Family Circle Cup in Charleston, South Carolina on Thursday, beaten 7-5, 6-4, by 17-year-old Tatiana Golovin of France in the third round.
Top seed Lindsay Davenport, number two Elena Dementieva and former world number one Justine Henin-Hardenne all advanced but fourth seeded Williams paid the price for an error-laden performance, particularly on her forehand.
Golovin will meet seventh seed Nadia Petrova of Russia in the quarter-finals.
"It was a comedy of errors," Williams said.
"She's definitely a good player but I don't think she came out there and beat me. I just kept making error after error."
Williams said the efforts of the past month, when she played back-to-back events in Miami, Amelia Island and here, had taken their toll.
"I just think I'm having a mental letdown from all the tennis I've been playing in the last four weeks, and I just felt pretty dead," she said.
In cold, windy conditions, Williams, who had struggled past Denisa Chladkova in her opening match on Wednesday, double-faulted three times in the first game to give 13th seed Golovin the early break.
REALLY SOLID
The American looked back on track when she broke back in the seventh game but Golovin, the world number 25, attacked the Williams forehand, broke again to lead 6-5 and then saved a break point on her own serve to take the opening set.
The second set went with serve until the seventh game when the Williams forehand failed again, handing Golovin the advantage and the French girl held on to serve out for her biggest win to date.
"I played against a few top-ten players already, and I always kept losing in three sets," Golovin said.
"I just really just stuck to my game. I was really solid and I didn't give her a lot of second serves to return. I really pressured her forehand, and I think that's was key."
Earlier, Petrova advanced to the last eight when she beat Croatian Jelena Kostanic 6-3, 6-3.
Former world number one Justine Henin-Hardenne set up a showdown with current number one Lindsay Davenport thanks to a 6-2, 6-3 drubbing of Iveta Benesova.
"It's going to be another level, for sure," Henin-Hardenne said.
"I think it's going to be a tough mission and especially because the surface is very fast and I know that Lindsay loves to hit winners from anywhere off the court.
"I'll have to play my best tennis, and I don't know if I'm ready for this. We'll see."
Top seed Davenport overpowered 16-year-old Ukrainian Viktoriya Kutuzova 6-3, 6-1 in the evening match.
Kutuzova showed enough to suggest she'll be a force in coming years as she recovered from 5-0 down to 5-3, but Davenport closed out the set and then eased through the second to reach the last eight.
DEMENTIEVA CRUISES
Russian second seed Elena Dementieva crushed Nuria Llagostera Vives 6-0, 6-3 to set up a quarter-final against unseeded Slovenian Katarina Srebotnik, who upset 11th seed Ai Sugiyama 6-1, 4-6, 6-1.
Dementieva hit five aces as she raced to a 6-0, 2-0 lead, and, after a mini-loss of concentration, gathered herself to ease to victory.
"The first set was so perfect for me that I think I just lost my concentration at the start of the second set," Dementieva said.
"It was quite difficult circumstances, with the wind and the cold -- I think it's even warmer in Moscow than here right now."
Nicole Vaidisova, the 15-year-old Czech, followed up her second-round win over third seed Anastasia Myskina with a gutsy 3-6, 6-4, 7-6 victory over 14th seed Shinobu Asagoe.
In the quarter-finals, she'll face eighth seed Patty Schnyder, who continued her smooth progress with a 6-4, 6-0 defeat of Klara Koukalova.
