The former heavyweight champ and his family were staying in Sin City over the New Year weekend (31Dec11-01Jan12) when he awoke to see a flashlight and hear rustling in his room.
But before Tyson got a chance to grab the intruder, the man fled, according to TMZ.com.
A spokesman for the hotel tells the website, "We have received a report of an incident that is currently under investigation. As always, guest safety is of the utmost importance."
The singer was in Portugal's capital for a concert on her Loud tour when she met the man who proceeded to insult her, but Rihanna quickly hit back and then called the hotel manager.
The Barbadian beauty tweeted yesterday: "I just met the most racist **** EVER!!! This man said the craziest shitt abt black women called us dogs, sluts, we don't look like s**t, we don't belong in the same hotels ... needless to say, the #NIGGA in me came out! Bajan accent and all! Lol! Turns out the hotel manager's black.
"Oh and he had the NERVE to diss black people in his Tighty whitey's!!!! SMH...and tbh a lil black wouldn't hurt him (sic)"
However, Rihanna did not let the stranger stop her from partying. The singer jetted into London yesterday for the remaining three UK dates on her tour and quickly set about celebrating with her crew.
She wrote on twitter: "My new residence tbh, LONDON TOWN O2 8,9,10 of 10!!! #LOUDtourUK
"We just had our end of year/tour Christmas party!!!! We turned it into an 80's prom, since I've never had one! It was sooo much FUN!!!!
"I'm decked out in lace, sequins, a giant bow, and hair spray!!!!! #80sBaby (sic)"
