The fin of a great white shark is seen swimming a past research boat in the waters off Gansbaai, South Africa. Olympic champion Michael Phelps lost to a simulated shark in the Discovery Channel's Shark Week special “Phelps vs. Shark: Great Gold vs. Great White,” which aired Sunday.

Michael Phelps has finally met his match in the water: a “great white shark.”

The Olympic champion swimmer was bested Sunday night in the Discovery Channel’s Shark Week special “Phelps vs. Shark: Great Gold vs. Great White.”

But Phelps didn’t swim with a real shark. He competed in the ocean against a computer-simulated fish based on data on the swimming speed of sharks.

Phelps was outfitted with a wetsuit and a monofin to mimic a shark’s powerful tail. He finished the 100-meter race in 38 seconds, 2seconds slower than the simulated shark.

Phelps tweeted Sunday that he’d like a rematch, but in warmer water.