http://www.youtube.com/watch?v=oqwvTI1t7fg
Alright, lemme start by saying I am a fan of The Ghost. That said, I hadn't seen this fight before, but it ain't a good look for him. Round 1 clearly belonged to Yordan. In the second, Yordan continued to find Guerrero and seemed to have much faster hands.
An accidental butt opened up a cut on Guerrero in the 2nd round, and he complained and time was called to have it looked at. Guerrero says he can't see and the fight is called off. ND.
No telling how the fight would have gone, although Yordan was clearly a quality fighter. IMO it looks like a pretty obvious quit on Guerrero's part. It was a bad cut, but it seems like he could have at least finished the first four rounds.