Schooling beat Phelps in the 100-meter butterfly, claiming his and Singapore's first gold medal in Olympic history.

During the victory lap after the race, Schooling turned to Phelps and said, "Dude this is crazy, out of this world, I don't know how to feel right now," according to The Guardian.

Phelps smiled and simply replied, "I know." 

For Schooling, beating Phelps also meant beating his swimming idol. Phelps and Schooling met for the first time in 2008. 

"They came to the country club that I trained at," Schooling told The Guardian. "Everyone just rushed up and was like 'it's Michael Phelps! It's Michael Phelps!' and I really wanted a picture ... It was very early in the morning and I was so shell shocked, I couldn't really open my mouth."

Now it's Phelps' turn to be shell-shocked, as Schooling put him in a position he's not used to: second place.