by Tim Furious, BETUS.COM – BET NOW

The UFC reaches its centennial this weekend with UFC 100 live at Mandalay Bay in Las Vegas. The UFC betting public is getting spoiled in this one, with two championship main events on the card.

The headlining championship bout will likely depend upon your perspective, but we’re going to start with the UFC Heavyweight Championship fight between title holder Brock Lesnar and interim champ Frank Mir. Not only is this a title fight, it’s also a rematch, as Lesnar faced Mir in his UFC debut back at UFC 81 in February 2008.

In that match Mir was the victor, winning by submission after locking Lesnar into a kneebar 1:30 into the first round. However, up to that point in the match Lesnar was in control, using his size and strength to get the advantage. Only by errantly leaving his leg vulnerable to Mir’s submission did he lose it and end up losing the fight. A more experienced Lesnar should be much more careful this time and avoid such a poor rookie mistake. That’s why Lesnar is a -240 favorite on the UFC odds in the rematch, while Mir clocks in at +190.

Saturday night’s other championship bout is a UFC Welterweight title fight between champion Georges St-Pierre and challenger Thiago Alves.

This will be St-Pierre’s first title defense since he manhandled B.J. Penn at UFC 94 in January. St-Pierre won by TKO when the referee stopped the fight after the fourth round. That fight is also remembered for the “Vaseline controversy” after Penn accused GSP of cheating by covering himself in the slippery substance. The claims were put to bed quickly, and considering how badly GSP pushed Penn around it would have made hardly any difference anyway.

Alves enters the bout having won seven straight fights, five by knockout. Overall he’s a lifetime 16-3 with 10 wins by KO. His last fight was at UFC 90 in October against Josh Koscheck. Despite all his recent success and his lengthy winning streak Alves will be up against another league of fighter when he faces GSP, who is currently tied with Fedor Emelianenko as the best pound-for-pound MMA fighter in the world at Yahoo! and sits among at least the Top 3 in most other rankings. That’s why he’s such a heavy underdog in the fight at +220 and GSP is a -300 favorite. Don’t fully count out Alves, though. As any UFC fan knows, it only takes one good punch to turn the tide in a match, and with Alves’ knockout power that’s definitely a possibility.