The bout took place way back in 2007 at UFC 69. At the time, GSP was riding a six fight winning streak, and had just avenged his previous loss to the legendary Matt Hughes. Serra had earned his title shot by winning TUF 4, and although he was widely respected, next to no one was saying he’d defeat GSP.
Well, Serra rocked the MMA world and then some by scoring a first round stoppage. You can watch the massive upset below.
The two battled again one year later and GSP reclaimed the belt by stopping Serra in round two.