Seattle Seahawks star DK Metcalf ran 10.37 seconds in the 100m at the Golden Games but failed to make the final.
“These are world-class athletes, very different than football,” said Metcalf, who missed out on a place at next month’s US Olympic trials.
American Cravon Gillespie won the 100m final in 9.96 in Walnut, California.
Great Britain’s CJ Ujah was fourth in 10.03 as he clocked the Olympic qualifying standard with his fastest time in the event since 2017.
There was British success in the women’s 800m as Jemma Reekie won in a personal best of one minute 58.27 seconds. Fellow Britons Laura Muir (1:58.46) and Adelle Tracey (1:59.50) were second and fourth respectively as the trio all met the Olympic qualifying standard.
Cindy Sember was just 0.02 from setting a British record as she finished second in the 100m hurdles with a personal best of 12.53, while Eilish McColgan was fourth in the women’s 1500m.