The 2012 bronze medallist, 34, finished in 9.80 seconds, beating 20-year-old Trayvon Bromell who qualified for his first Olympics.
World champion Allyson Felix also set the year's fastest time in the women's 400m.
The 30-year-old, who won 200m gold in London, finished in 49.68secs despite still recovering from an ankle injury.
"Two months ago I couldn't even walk. Somehow we found a way," Felix said.
Meanwhile Yohan Blake claimed victory in the 200m Jamaican Olympic trials, finishing in 20.29 seconds - his best time since finishing second to Usain Bolt in 19.44 seconds at London 2012.
Bolt was forced to withdraw from the trials on Saturday after suffering a hamstring tear in the 100m semi-finals.
Blake, who also won the 100m, said that he did not think Bolt's injury was serious enough to rule him out of Rio.
