Labelled the "next Michael Phelps"[3] following his breakthrough four years ago at the 2017 World Championships, the U.S.' megastar Caeleb Dressel finally won his first individual Olympic title.

Dressel used his signature explosive start to gain a strong advantage on the field and touch first at the 50, before narrowly holding on in the final lap to clock a new Olympic record of 47.02.

French swimmer Maxime Grousset could not emulate the feats of his compatriot Alain Bernard, the 2008 Olympic Champion, slipping off the podium to fourth place.

Romanian 16-year old David Popovici (48.04) was unable to replicate his stunning 47.30 from earlier in the year, falling to seventh while Hungary's Nandor Nemeth (48.10) rounded out the championship field.

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.