In the first swimming final at these Games, the U.S.' Chase Kalisz used a scintillating breaststroke leg to upgrade his silver from Rio five years earlier with an Olympic title in the event.

Australia's Brendon Smith (4:10.38) almost pulled off a last-to-first victory, sitting in eighth heading into the freestyle before splitting a blistering 56.3 to take bronze.

France's Léon Marchand (4:11.16), New Zealand's Lewis Clareburt (4:11.22) and Italy's Alberto Razzetti rounded out the tight field, with first to eighth separated by just two seconds.

Notable swimmers to miss the final included Japan's reigning World champion Daiya Seto who finished ninth in the heats, only 0.32 seconds behind the last qualifier.

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.