American sprinter Tyson Gay beat the 100m world record but was denied the official time because of strong winds at the Reebok Grand Prix in New York.
Gay enjoyed favourable conditions in to set an impressive time
Gay's wind-assisted 9.76 seconds was 0.01 seconds inside the record.
The 24-year-old beat a strong field, including Olympic 200m champion Shawn Crawford and Derrick Atkins, who had the second-fastest time this year.
"I don't really want to chase the world record. I'm just so happy to beat some tough competitors," said Gay.
"I'm not frustrated at all. I had a bad feeling about the wind. It can't always be perfect."
Gay, who ended last year ranked number one in the world in the 200m and second in the 100m, proved he was in good form with a stunning 100m win at a meeting in Los Angeles on 20 May.
He clocked a time of 9.79 but that was also wind-assisted and so his 9.84 remains his official personal best.
Jamaica's Asafa Powell and American Justin Gatlin currently share the world record of 9.77.
But world and Olympic champion Gatlin could be stripped of his titles after testing positive for illegal quantities of testosterone in April 2006.
Gatlin, who claims he is innocent of deliberate doping, is set to face a US Anti-Doping Agency (USADA) arbitration hearing after admitting a violation in order to reduce a possible eight-year ban.