By A Mystery Man Writer
He beat the long-standing record by a smashing 1.34 seconds on Sunday, making him the world record holder in the long course 400m individual medley.
How Léon Marchand Became the Best Swimmer in the World
Leon Marchand Continues to Prove His Status as World's Best Swimmer
Leon Marchand, 21-year-old French swimming star, breaks Michael Phelps' last remaining world record
Michael Phelps
FLASH Leon Marchand Downs Michael Phelps' 400 IM World Record
Marchand nearly tops a Michael Phelps World Record in Worlds 400 IM
French star Leon Marchand breaks Michael Phelps' last individual world record, the 400m IM - CBS Baltimore
Leon Marchand Knocks Michael Phelps From Record Books
Katie Ledecky's 800 free win breaks golds tie with Michael Phelps - ESPN
Marchand smashes Phelps' 15-year record at worlds – FBC News