McKayla, 16, nailed the vault, showcasing the Amanar - a tricky, near-impossible skill that just a handful of gymnasts in the world can do - with such precision, her coach couldn't believe her score wasn't the maximum.
"It. Was. The. Best. Vault. Ever," Marta Karolyi said.
Watch below and you'll see, it's hard to argue that:
You'll have another chance to watch McKayla Maroney go for gold this week in the individual vault event. Don't be surprised to see her post a 16.5 then.