Justin Gatlin edged out LaShawn Merritt and the rest of the field in a star-studded 200-metre final at the United States trials.
Gatlin, who won the men's 100-metre final earlier this week, got out to a sizeable lead before powering home in 19.75 seconds to beat Merritt (19.79secs).
Ameer Webb earned his berth at the Rio Olympics by coming in third at 20 seconds flat.
Bernard Lagat decided to compete in the 5,000-metre run on a whim and the 41-year-old claimed the national title.
The Kenyan native, who began running as an American in 2005, will get a chance to add to the silver and bronze medals he won in 2004 and 2000 respectively.
"I had a lot of confidence. I was not surprised what I did today because I've been training hard," Lagat said after the race.
"To make not just one, but five Olympics... this is incredible."