This may be one of the most random videos you'll see all day.

"Fast & Furious" star Vin Diesel dedicated a very special karaoke performance to his Facebook fans last night -- tackling Rihanna's falsetto-filled new single, "Stay."

With the singer's very nude music video playing in the background, the blazer-clad actor looked confident while trying to hit some very high notes.

If we're pretending to be Randy Jackson for a minute, yes, it's a little "pitchy" -- but also a lot of fun.

Check out his performance above. How do you think he did? 

Want more Vin? Check out the extended "Fast & Furious 6" trailer below: