World record holder Usain Bolt withdrew from Jamaica's Olympic trials only minutes before the 100m final on Friday night.
His executive manager Nugent Walker confirmed the news, less than 20 minutes before the race.
"He, Bolt, is out of the remainder of the championship on medical exemption," Walker said.
Bolt's withdrawal does not mean he will miss the Olympics in Rio de Janeiro, where he is expected to defend his titles in the 100 and 200 metres and he still hopes to make the Anniversary Games in London later this month.
He told social media: "After feeling discomfort in my hamstring after the first round last night and then again in the semi-final tonight I was examined by the Chief Doctor of the National Championships and diagnosed with a grade 1 tear.
"I have submitted a medical exemption to be excused from the 100m final and the remainder of the National Championships. I will seek treatment immediately and hope to show fitness at the London Anniversary Games on July 22 to earn selection for the Olympic Games in Rio."
Unlike the United States, where the first three finishers in the trials win Olympic berths, Jamaica's selection policy allows medical exemptions.
Bolt had clocked 10.04 seconds to win the first semi-final after a poor start and was due to square off in the final against Yohan Blake, who clocked 9.95 to win the other semi-final.