The Wrestler star, 57, was celebrating being crowned International Man of the Year at last September's (09) GQ Man of the Year awards in London when he befriended the members of an English rugby team.
The Huddersfield Giants players challenged the star to a round of friendly arm wrestling matches, and Rourke held his own until one hulking player stepped up and tore the actor's arm muscle from the bone.
Rourke recalls, "They treated me like their long-lost brother. We started arm wrestling. I did OK with two of them and they were very surprised. Another guy came walking through the door - he was the size of a house. I did him with my left hand and then he just killed me with the right. I didn't go all the way down and it (the muscle) ripped in half. The next day it all turned black."
Rourke underwent surgery in Heidelberg, Germany to have the muscle reattached - but he waited too long., and now the actor's arm is doomed to be deformed.
He explains, "I was in the hospital eight or nine days. Two weeks ago I found out it (the surgery) didn't work. The tendon didn't take because you're supposed to do it a day or two afterwards, but I waited six months... It got atrophied. I have full use of the arm and I can do whatever I used to do, it just looks a little retarded."