Caeleb Dressel smashes Michael Phelps' world record in 100m butterfly at World Swimming Championships

There was an error

Sorry, this video is temporarily unavailable. Please try again later.

American Caeleb Dressel smashes Michael Phelps' world record in the semi-final of the 100m butterfly at the World Swimming Championships with a time of 49.50 seconds.

WATCH MORE: 'Swimming chose me': Is Caeleb Dressel the next Michael Phelps?

WATCH MORE: 'Adam Peaty take a bow!' - GB star wins gold in 50m breaststroke