Ryan Day says his viral golf cart crash sucked all the mojo out of his national championship experience ... joking he felt like he was living out a scene from "Austin Powers" -- and the moment brought him back to reality real quick.

The Ohio State Buckeyes' head coach hung out with Jimmy Fallon on 'The Tonight Show' this week ... and, of course, he couldn't talk about the big win without addressing the viral golf cart incident from the tunnels of the Caesars Superdome after the victory.

Day said he hoped to use those few minutes on the cart to take a deep breath and prepare for the press conference ... but the woman behind the wheel treated it like a NASCAR race.

"We are just gunning it through the field," he said. "Just dodging around people, and I'm grabbing on like this, and then we took the corner and hit the wall!"

The 45-year-old coach joked that the ordeal was humbling ... and he couldn't help but make a Mike Myers reference right after the collision.

Luckily, everyone walked away from the incident without sustaining any injuries. While the Buckeyes' head coach didn't find it very amusing at the time, his quarterback Will Howard did -- and he told TMZ Sports last week he felt worse for the woman driving than anyone else.

"The poor girl," he said. "I feel terrible for her. Hopefully she's bouncing back."