After competing in sport karate competitions at a young age, Georges St. Pierre began his professional mixed martial arts career in 2002, defeating notable fighters Ivan Menjivar and Pete Spratt, before debuting in the UFC in 2004 with wins over Karo Parisyan and Jay Hieron. He was then given a title match with former champion Matt Hughes for the vacant UFC Welterweight Championship. However, as St. Pierre claims, his nerves caught up to him and he overcommitted on a kimura attempt, that Hughes was able to counter into an armbar for a submission victory at 4:59 of the first round.
After putting together one of the most impressive winning streaks in welterweight history with consecutive demolitions of Jason “Mayhem” Miller, Frank Trigg, Sean Sherk, and BJ Penn, St. Pierre took the UFC Welterweight Championship from Matt Hughes at UFC 65 in 2006. Although he lost his first title defense to heavy underdog Matt Serra, St. Pierre rebounded by beating Josh Koscheck and then Matt Hughes for the interim championship. He then reclaimed the title in a rematch one year after losing it at UFC 83.
He is universally regarded as one of the top pound-for-pound fighters in the world, having dismantled many of the top fighters in the division since that time, Josh Koscheck (again), Jon Fitch, Thiago Alves, Penn (for a second time), and Jake Shields. Unfortunately, GSP tore his ACL while training for his next fight, and did not compete for 19 months.
In UFC 154 St. Pierre squared off against interim welterweight champion, Carlos Condit to unify the belt. After being dealt a devastating head kick and flurry of punches in the third round, Georges came back to win a unanimous decision. He would then face Nick Diaz, whom St. Pierre has personally requested to fight, due to comments made by Diaz. At UFC 158 they would finally meet and GSP would use his wrestling to take down and frustrate Diaz en route to a Unanimous Decision victory.