Pro skier Henrik Harlaut was knocked out cold Saturday during an X Games Aspen event ... and the footage is frightening.
It all went down during the Men's Slopestyle finals ... when Harlaut landed a trick the wrong way and took a gnarly tumble -- leaving the 23 year-old motionless as medics rushed in to help.
The Swedish skier eventually sat up before being stretchered off the mountain ... and waved to everyone letting them know he's OK while plastering a giant smile across his face.
You gotta watch the video ... dude looks lucky to be alive.
Waiting for your permission to load the comments.