gettyimages-1565175145-1.jpg
Getty Images

French swimmer Leon Marchand broke Michael Phelps' last individual world record in the men's 400-meter individual medley on Sunday, the first day of the World Aquatics Championships. Phelps was on the mic calling the race when the 21-year-old set a new record of 4:02.50 in Fukuoka, Japan.

Phelps is the most decorated Olympian of all time with a total of 28 medals, 23 of them gold. He retired after the 2016 Rio Games, but before then he etched his name into the history books multiple times. The record Marchand broke on Sunday was the 4:03.84 set by Phelps at the 2008 Beijing Olympics. Marchand had come within 0.44 of Phelps' record at last year's worlds in Budapest, and it looks like he finally got over the hump.

"That was insane, one of the most painful things I've done. It was amazing to do it here and the time is crazy," Marchand said poolside, as reported by the official Olympics website.

"It's excellent, I train everyday for that. I'm two seconds faster than my previous record, I beat the world record, it's amazing… I don't know what to say, I'm so happy."

When Marchand beat Phelps' time, Phelps stood up and clapped. Phelps also gave the new record-holder his gold medal at the ceremony.

"He was very impressed by the time," Marchand said. "He was commenting on the race so it was pretty cool to see that. He just told me so many things and also what to improve on next time. It's a great day.

"I think I'm handling the pressure pretty well right now. It's not perfect. I can get better -- and I have one year to improve."

Marchand trains at Arizona State under Bob Bowman, who is Phelps' longtime coach. 

The French rising star is set to compete in three more races in Fukuoka -- the 200-meter individual medley, 200-meter butterfly and 200-meter breaststroke. While it's still a year away, Marchand will be a favorite during the 2024 Paris Olympics and will get the home-crowd advantage.