Britain's Alison Sheppard has failed to reach the women's Olympic 50m freestyle final in Athens.
The 31-year-old Commonwealth gold medallist came home in 25.36 seconds to finish in fifth place in the first semi-final at the Acquatics Centre.
American Kara Lynn Joyce won Sheppard's race in 25.06 to go through.
Defending champion Inge de Bruijn of the Netherlands was the fastest qualifier, winning the second semi-final in 24.56.
Sheppard set a record for a British swimmer by competing at her fifth Olympics but she was a little disappointed with her final appearance in Athens.
"It just really wasn't my night," said Sheppard.
"I just couldn't raise my game and you have to take the bad with the good.
"I've really enjoyed my experience at the Olympics, it's been the best I've
ever been to."