For the Discovery Channel's annual Shark Week, Michael Phelps finally met his swimming match in the form of a Great White.

The retired Olympic hero swam the stretch of open ocean in South Africa in 38.1 seconds to the shark's 36.1. To level the playing field slightly, Phelps was allowed to swim with a monofin.

The Discovery Channel had given the show a huge build up, but not everybody was left impressed with the finished product. Why? Because it turns out the shark was, well, not really a shark. Rather than having Phelps go head-to-head with the feared creature, scientists instead used a computer simulation. Twitter, it's fair to say, wasn't happy.

Still,  viewers would get to see the swimmer square off with a real Great White at one point — albeit from the safety of a cage.

Did you watch the show? Let us know your thoughts in the comments.

In other news, Draymond Green and Conor McGregor are throwing shade at each other on Twitter.