The dazzling US Open run by American teenager Melanie Oudin ended abruptly on Wednesday in a hail of unforced errors, while Roger Federer was tested but marched into his 22nd consecutive grand slam semi-final.
Ninth-seeded Dane Caroline Wozniacki was steady, if unspectacular, in defeating the unseeded Oudin 6-2 6-2 to reach the semi-finals of the year's final grand slam.
"I've had a great run this tournament," said the 17-year-old Oudin. "I'm a perfectionist, so... losing isn't good enough for me. Today I was a little bit fragile."
Top seed Federer overcame an inspired comeback effort by Robin Soderling to beat the 25-year-old Swede 6-0 6-3 6-7 7-6, winning the final-set tiebreaker 8-6.
"It was so close towards the end," said Federer, who has beaten Soderling in all 12 career meetings, including at Wimbledon and the French Open this year.
"It's a great relief to come through. He started to play better and better as the match went on. I knew he was going to be tough but the beginning was bit too easy.
"All of sudden he found his way into the match."
In the semi-finals, the five-times defending champion will face fourth seed Novak Djokovic, who advanced with a 7-6 1-6 7-5 6-2 victory over Spain's Fernando Verdasco, the 10th seed.
Elsewhere, Belgium's unseeded Yanina Wickmayer dispatched Ukraine's Kateryna Bondarenko 7-5 6-4 and set up a semi-final encounter with Wozniacki.
But the big news of Day 10 at Flushing Meadows was the quiet elimination of Oudin, the diminutive Georgian who failed to respond to the urging of the 23,000 fans at Arthur Ashe Stadium.
Oudin, who beat fourth seed Elena Dementieva and former champion Maria Sharapova en route to the quarter-finals, had 43 unforced errors during the 88-minute match against Wozniacki and only seven winners from her chief weapon, the forehand.
"I started off slow," said Oudin, ranked number 70. "I wasn't able to come back. She's such a strong player. She doesn't give you anything for free. She plays incredible defence, makes me hit a thousand balls.
"I don't know what else I could have done. I could have been more consistent and been more patient but she really made me think out there and made me have to hit a winner to win the point. I was a little too impatient."
The 19-year-old Wozniacki kept the pressure on Oudin, registering only five winners, while letting her opponent spray the ball all around the stadium on a blustery night.
"I'm thinking well on the court," said Wozniacki. "I make the right decisions. I'm a fighter. I run well, but I'm also capable of changing the rhythm, be aggressive.
"I'm an all around player."
She will now face Wickmayer, Belgium's top-ranked player, who had failed to advance past the first round in five of her six previous career grand slam appearances.
The 19-year-old Wickmayer, ranked 50th, admits to being amazed at her run.
"Before this, my best (grand slam) result was second round," she said. "So of course when you get to the third, fourth round, you start surprising yourself.
"But actually, I've been staying pretty calm. I've worked really hard for this."
The rash of upsets among the women had left only number two seed and three-times champion Serena Williams left in the draw among the top eight. She will face Belgian Kim Clijsters, the 2005 champion, in the other semi-final.
Clijsters is returning from a two-year break from the game to start a family and has only been back on tour a few weeks.
Djokovic, a Flushing Meadows finalist in 2007, had 10 aces and landed 67 percent of his first serves to reach his third consecutive U.S. Open semi-final.
"It feels great," said fourth seed Djokovic. "Mentally it was very important for me to overcome today's challenge and to be able to win and to get to the semi-finals first time in the grand slams in 2009.
"I like playing here. Starting from the surface, which is quite suitable to my game, the fans, the atmosphere, the entertainment, the show.
"The results that I've made in the past three years show how much enjoyment I have playing here."