The world’s most decorated Olympian may have finally met his match.

Phelps raced an 8-foot great white shark (sort of) in open water Tuesday as part of Discovery Channel’s Shark Week. The race aired Sunday.

The episode was called “Phelps vs. shark: Great gold vs. great white.”

Phelps wore a special wet suit with a monofin attached to his feet. The 100-meters contest took place in the cold waters off the South African coast.

The fastest Phelps ever swam to reach a gold medal was roughly 6 miles per hour, but with the monofin, he doubled that speed. Great whites can swim up to 25 miles per hour.

The shark took the gold medal in this swim.

But only by 2 seconds.

Phelps swam the races alone -- CGI was used to display the sharks racing alongside him. He swam in warmer waters "against" a hammerhead and reef sharks, besting the latter by .2 seconds.

Phelps said he felt totally safe the whole time, surrounded by safety divers during the race. He told Jimmy Fallon on The Tonight Show that he originally wanted to do it without the protective cage.

“I told my wife I wanted to do it without a cage, and she said, ‘Well we have a family. I don’t know if that’s really going to fly,” Phelps told Fallon.

According to an Instagram post, swimming with a great white is something Phelps has always dreamed of doing.

I was able to do something that I had always wanted to do. Be in a cage and dive with great White sharks 🦈!! #bucketlist

A post shared by Michael Phelps (@m_phelps00) on