Caeleb Dressel broke his own men's 100m butterfly world record en route to winning is second individual gold medal — his third overall — at the Tokyo Olympics.
Dressel touched first in 49.45, lowering his mark set at the 2019 World Championships by .05.
The Northeast Florida native got off the blocks in .60, the quickest reaction time of the heat. He then took at .65 lead over Hungary's Kristof Milak at the turn and beat the world record line coming home to set the all-time mark.
Milak took silver as Switzerland's Noe Ponti took bronze.
The 100 fly final was the first of three events Dressel is scheduled to race in Saturday's finals session. In the span of just over 70 minutes, he will also race the semifinals of the 50m freestyle and participate in the mixed medley relay for the United States.
