Michael Phelps split his swim cap seconds before winning 21st gold medal

Published Nov. 15, 2016 2:14 p.m. ET

Chris Chase

Turns out Michael Phelps isn't as unbreakable as we thought.

Seconds before he was set to dive into the pool to anchor the U.S. 4x200m freestyle relay Tuesday night, Phelps ducked his head, spread out his swim cap and, like he's done thousands of times in his life, put it on his head. And then that thing split like a celebrity marriage.

Phelps looked up at the scoreboard, realizing he had just a little time to rectify the situation, so he called out to teammate Connor Dwyer, who'd already swum, and asked for his cap.

Then he asked for Dwyer's assistance to put it on. (It's harder than it looks.) Looks like somebody was ... using his head.

Dwyer swam a ridiculously fast leg of the relay but that's where the magic stopped. He was unable to get the cap onto Phelps' head. Pssh, some teammate. Thus, Phelps took things into his own hands.

And like you'd expect from a man who'd won one of the biggest golds of his career about 54 minutes earlier, he nailed it.

Like a G.O.A.T..

If you're wondering why Phelps needed a cap when he already had a cap on, it's a good question. Most swimmers wear two caps at meets. The first is a tight-fitting lid usually made of lycra (that's what Phelps was wearing). It pushes down hair, smooths out the dome and covers those pesky goggle straps. The second, the one that split for Phelps, is a relatively recent equipment innovation made of silicone that helps reduce drag in the water. It works so well that you'll sometimes even see swimmer who shave their heads wear the caps. Silicone > skull. Swimmers generally double-up caps just for meets, the same way they shave just for meets. A little extra drag in practice doesn't hurt and may actually be preferable, like a batting donut.

This isn't the first equipment-related mishap Phelps has had in the Games. In 2008, his goggles filled with water when he dove into the pool in the 200 fly (the same event he won Tuesday night). There was no recourse that time. Partially blinded, he had to count his strokes and anticipate where the wall was. It almost cost him his record eight gold medals.

The Americans had given Phelps a body-length headed into his leg, so he could have gone without a cap and still easily won. Heck, he could have worn jorts, a cut-off Metallica T-shirt he definitely would have borrowed from Ryan Lochte and Boomer's headphones and still brought home the W.