I didn't know that Alberto Del Rios fought Cro Cop

[The Naitch]

I originally heard this from Mauro Ranallo from the MMA Show

Then I looked it up on Wiki

After making his professional wrestling debut in 2000, Dos Caras, Jr. decided to try his hand at mixed martial arts (MMA). After training with MMA fighter and trainer Marco Ruas, Caras, Jr. made his debut for Japanse MMA organisation Deep.[8] In his first match he demonstrated his professional wrestling background by executing a Belly to belly suplex on opponent Kengo Watanabe, a move that broke Watanabe's arm to end the match.[36] In Caras, Jr.'s second match he lost to Watanabe by submission in the second round.[36] In 2003 Japanese MMA organization Pride Fighting Championships put out an open challenge for anyone to face their top star Mirko "Cro Cop" Filipović in a match. Over 50 competitors stepped forward, including a couple of Japanese professional wrestlers, out of the group Dos Caras, Jr. was chosen since he had an MMA background and also a "name" due to his and his father's association with professional wrestling. Pride rules were amended to allow Dos Caras, Jr. to wear his signature mask in the match against Filipović.[37] On October 5, 2003 Dos Caras, Jr. faced Cro Cop with his father, Dos Caras, and his cousin, Sicodelico, Jr. in his corner. The match lasted 46 seconds before Filipović hit Dos Caras, Jr. with one of his signature moves, the left high kick, and knocked him out.[38] Following the quick loss, Dos Caras, Jr. has competed in eight further MMA matches, attaining 6 wins and only 2 defeats.[36]