Michelle Wie suffered agony at the John Deere Classic as dropped shots on two of her last four holes saw her miss the cut by two strokes.
SECOND ROUND LEADERBOARD
US unless stated
-13 JL Lewis
-11 Hunter Mahon, Shigeki Maruyama (Jpn)
-10 Brandt Jobe
The 15-year-old was four under with four to play but a double bogey at the sixth followed by a bogey cost her.
"Those two holes killed me," said Wie, hoping to become the first woman since 1945 to make a PGA Tour cut.
Wie also missed out on qualifying for the Open by being the top finisher without an invitation to St Andrews.
Wie, making her third appearance on the US tour, made a solid start in her bid on Thursday with an opening round of 70.
And she continued that form on Friday, making the turn in 33 to move up from 70th to 40th.
Starting on the 10th, she birdied three of her first five holes before a bogey at the 15th halted her progress.
However, another birdie at the 18th left her in good shape to become the first woman since Babe Zaharias to make the halfway cut on the men's circuit.
But after a string of pars on the front nine, Wie's round fell apart over the closing four holes.
After disasters on the sixth and seventh, Wie could only par the last two holes to finish on one under, two shots adrift of the projected cut.
"I finished under par, so I guess that counts for something," said the disappointed teenager.
JL Lewis, the 1999 champion, fired a six-under-par 65 after an opening round 64 to move to the top of the John Deere leaderboard at 13-under 129.
Lewis was full of praise for Wie.
"It's pretty phenomenal," Lewis said. "Has there ever been anybody that age, man or woman, that could play in a tour event at age 15?
"She came out here and almost broke par twice. More power to her. That's pretty impressive."
First-round leader Hunter Mahan, who shot a 63 on Thursday, shot a second-round 68 to lie two strokes behind Lewis.