U.S. megastar Caeleb Dressel fended off a late charge by Kristóf Milák to win his second individual Olympic title in a world record of 49.45.

Meanwhile Milák, the 200 m butterfly champion from earlier in the week, could not overtake Dressel but touched in a European record of 49.68 to win silver and pass Michael Phelps and Milorad Čavić to become the second fastest performer in history.

Matching his Polish record from the heats, Poland's Jakub Majerski (50.92) tied for fifth with Australia's Matthew Temple who could not replicate his stunning 50.45 trials performance.

Guatemala's Luis Martínez touched in a national record of 51.09 to take seventh, while Bulgaria's Josif Miladinov (51.49) was a shade off his times in the earlier rounds to finish in eighth.

Up to one swimmer per NOC meeting that time is eligible for selection, allocated by world ranking until the maximum quota for all swimming events is reached.