There is always a case for the underdog.
Thiago Alves's takedown defense and striking were thought impenetrable.
Josh Koscheck and Dan Hardy had power punches and Jake Shields had uncanny submission abilities.
Up next, however, dominant welterweight champion Georges St. Pierre faces Carlos "The Natural Born Killer" Condit.
Aside from BJ Penn, Condit is the most dangerous overall opponent GSP has faced. But compared to former lightweight champ Penn, Condit can maintain a higher pace and is notably bigger for the division.
Many will be tempted to overlook Condit, but that could be a huge mistake and here are five reasons why.
I am not sure how many fighters can start off ferocious and then only become more ferocious the deeper the fight goes.
Carlos Condit can (new slogan?).
In tough fights against fellow young top welterweights Jake Ellenberger and Rory MacDonald, Condit's fighting spirit absolutely took over as the fights wore on.
Oh yeah, he has also finished 26 fights.
At only 27-years of age, "The Natural Born Killer" already has obtained an impressively robust record at 27-5.
Many fans will also remember Condit as the long reigning WEC welterweight champion, so he definitely has experience competing in big championship fights and going into deep waters.
Actually, I dare you to claim a more experienced fighter at that age who did not become or is not already a UFC champion.
St. Pierre will be facing as versatile a striking arsenal as there is come UFC 137.
Condit fights rangy, yet is still powerful as he presses forward with punches, kicks, knees and elbows.
His last two fights earned him "knockout of the night." First-round KOs over ranked fighters who had never been knocked out in their entire careers.
Against 90 percent of his opposition, GSP can usually employ a relatively conservative top-control-based ground game on his opponents.
I do not think he will be able to against Condit. Condit's size, aggression and grappling prowess might simply be too formidable.
Judo expert Dong Hyun Kim got reversed by Condit.
After securing a couple takedowns, GSP's understudy Rory MacDonald wanted nothing to do with Condit's ground game.
Trying to grind out rounds is a risky proposition against the likes of Condit.
GSP is no doubt a brilliant champion. He knows how to defend his title and pick his opponents apart, disabling their routes to victory.
But Condit is on even footing. He is surging and he has momentum.
Both are in their prime. Greg Jackson, the yoda of MMA, regularly trains both of these fighters and thus will give no added benefit one way or the other for this particular confrontation.
St. Pierre could very well defend his title again, but I think we are poised to see one of the greatest welterweight fights of all time.