Qualifier Julie Coin scored the biggest upset in US Open women's open era history on Thursday, sending world No 1 and top seed Ana Ivanovic crashing out in the second round.
Coin, who is ranked 188th in the world, was making her Grand Slam debut after successfully coming through the qualifying rounds.
She had tried but failed earlier this year to qualify for the other three Grand Slams -- Australian Open, French Open and Wimbledon.
The 25-year-old Coin clinched the victory on her third match point in the one hour, 57 minute match at the main Arthur Ashe Stadium.
"Today I felt nervous at the beginning and then it went away," said Coin, of France. "I don't know how I did it.
"I am not thinking about anything right now. Just enjoying the moment."
Ivanovic looked like the more nervous of the two in the deciding third set. She posted a total of eight double faults and made 37 unforced errors to 26 for Coin.
"This is very disappointing to me but something I have to accept," Ivanovic said. "I never saw her (Coin) play before so I didn't know what to expect.
"She played a lot better than I expected. She served very well."
Ivanovic, of Serbia, converted just one of her eight break-point chances and didn't record an ace.
She managed to survive two match points before going down in one of the biggest upsets in women's tennis history.
"I kept thinking play your game and get your first serve in," Coin said.
Until Coin's win, the previous earliest exit by the top seed at the US Open in the modern era was when Billie Jean King was ousted in the third round of the 1973 tournament.
Earlier this year at Wimbledon, No. 1 ranked Ivanovic lost to 133rd ranked Zheng Jie of China 6-1, 6-4 and in 2005, No. 1 Lindsay Davenport was beaten by 133rd ranked Kim Clijsters in three sets at the WTA Indian Wells tournament in California.
Coin moves through to the next round where she will play French countrywoman Amelie Mauresmo.
"It will be like playing a No. 1 because she used to be No 1," Coin said of Mauresmo.
Coin, who broke Ivanovic's serve five times, double faulted on her first match point. Her second match point came two points later and it took a superb crosscourt forehand right down the line for Ivanovic to stay in the game.
Coin clinched the win when Ivanovic sailed a forehand wide and long on the third match point.
Ivanovic has not had a long reign at number one. Her stay at the top was interrupted for a week earlier this month, but she since regained the top spot in the WTA rankings.
The six-foot-one Ivanovic came into the final Grand Slam of the year complaining about a lack of preparation due to injuries.
But she wasn't making any excuses on Thursday.
"Today I didn't feel it," she said of the thumb. "I'm just happy to be back on track without pain.
"Now all I have to do is put some hard yards on the court and go back out there and work hard."
Sixth seed Dinara Safina advanced to the third round by beating Roberta Vinci of Italy 6-4, 6-3 in a second round match.
It has been a breakthrough season for Safina who has won three of her eight career titles in 2008. She reached the final at the Beijing Olympics but had to settle for silver after losing to Russian compatriot Elena Dementieva.
"I think it still could be better," she said. "There is more room to improve. Hopefully in the next match I can do better."
Serena and Venus Williams rolled over their opponents on Thursday with Serena defeating Elena Vesnina of Russia 6-1, 6-1 and Venus brushing aside 113th ranked Rossana De Los Rios 6-0, 6-3.
Serena needed just 58 minutes to dispatch Vesnina who is ranked 71st in world.
Asked if she would have preferred had a more competitive match, Serena said she likes to get them over quick.
"Not too many long rallies but I am serving well," said the fourth seeded Serena.
The seventh-seeded Venus moves through to the third round where she will play Alona Bondarenko who beat Sabine Lisicki 6-4, 1-6, 6-4 on Thursday.
Serena next faces Japanese veteran Ai Sugiyama.
"She's pretty much relentless," said Serena. "I better be ready. That girl is a tough cookie."
Sugiyama rallied to beat Olga Govortsova of Belarus 4-6, 7-6 (7/4), 6-1.
The Japanese men were also celebrating on Thursday as Kei Nishikori advanced to the third round when Roko Karanusic, of Croatia, retired at the end of the second set with the Japanese teen leading 6-1, 7-5.
Nishikori, who is playing in his first US Open, will face fourth seed David Ferrer, of Spain.
"I tried to go to the net more often, because he was using the slice a lot," Nishikori said. "I tried to make more first serves. He gets more nervous when I make my first serve."