Suzann Pettersen won't be successfully defending her title after Jodi Ewart eliminated the third seed in Thursday's first round of the Sybase Match Play Championship.
Ewart, the 62nd seed, bested Pettersen, 3 & 1 at Hamilton Farm Golf Club.
"Just played awful from the fairway to the green," said Pettersen. "I missed more greens today than I have all year."
Pettersen actually won the first two holes, but took a 1-up lead to the turn. Ewart captured three holes in a row from the 11th to move 2-up, but the defending champion clawed back with a victory at the 14th.
Ewart all but closed Pettersen out with a birdie and a win at the 16th. Pettersen would need to take the last two holes to force extras, but she conceded the 17th and the match to Ewart.
"On paper, I'm not supposed to win, so there's no pressure on me," explained Ewart. "I just went out there and played really fearless golf because I was attacking pins."
Pettersen wasn't the only top-10 player to lose on Thursday.
Ai Miyazato, No. 4, lost to Mariajo Uribe, 2-up in the final first-round match.
Paula Creamer, the eighth-overall seed, fell to No. 57 Jennifer Johnson, 2 & 1.
Brittany Lincicome, ranked ninth, lost to Ryann O'Toole, 2 & 1.
World No. 1 and top overall seed Yani Tseng earned a hard-fought, 1-up victory over No. 64 Jeong Jang. On the 18th, Jang had six feet to square the match and go to a playoff hole, but she missed and Tseng advanced.
"It's a tough day for me today and I feel I'm pretty lucky to win a match today," said Tseng. "Hopefully tomorrow it's another new day and hopefully tomorrow I'll drop more putts."
With four top-10 players knocked out on Thursday, the brackets are already a mess.
Tseng, the top player in the Patty Berg bracket, will meet Katie Futcher on Friday. Other winners in the Berg bracket were: Candie Kung, Haeji Kang, Johnson, Karine Icher, O'Toole and Julieta Granada.
After Miyazato's loss on Thursday, the top player left in the Kathy Whitworth bracket is No. 5 overall seed, Cristie Kerr. She advanced with a 2 & 1 victory over Belen Mozo.
Kerr will take on Vicky Hurst in the second round and also moving on in the Whitworth bracket were: Uribe, Katherine Hull, So Yeon Ryu, Mina Harigae, who knocked out Michelle Wie, Angela Stanford and Eun-Hee Ji.
The second seed in the tournament, Na Yeon Choi, dispatched Grace Park, 2-up Thursday to set up a second-round bout with Jenny Shin, a 4 & 2 victor over Jimin Kang.
Morgan Pressel, Inbee Park, Jiyai Shin, Anna Nordqvist, Amy Yang and Natalie Gulbis also emerged from the Mickey Wright bracket. Gulbis' 1-up squeaker over Mika Miyazato was the only upset in that part of the draw.
Ewart's shocking win over Pettersen left Stacy Lewis as the highest seed in the Annika Sorenstam bracket. Lewis punched her ticket into the second round with a 4 & 3 drubbing of Pat Hurst.
Ewart will face Sophie Gustafson on Friday, while Lewis drew Sandra Gal. Other winners in the Sorenstam side were Karrie Webb, Azahara Munoz, Sun Young Yoo and Jessica Korda.
NOTES: No first-round match went to extra holes...This is the third year of the tournament and Yoo won the inaugural event in 2010...The second round is on tap for Friday with the third round and quarterfinals scheduled for Saturday and the semifinals and final on Sunday.