The UFC has two legendary welterweights facing off in the main event of UFC 137 on Saturday night as B.J. Penn takes on Nick Diaz.

Penn is a former UFC welterweight and lightweight champion while Nick Diaz was the Strikeforce welterweight champion prior to leaving the organization for greener pastures.

Penn (16-7-2) comes into this three-round contest as the favorite over Diaz (26-7-1), as Penn has odds of -125 to top Diaz, who has a money line of -105. Both fighters have similar styles as each relies on boxing and jiu-jitsu to win fights. Penn may have the edge in regards to wrestling, but Diaz will have a big size edge in terms of mass and reach. Both fighters will be sure to leave everything in the octagon, which makes this fight very interesting.

The co-main event also has a very competitive contest as heavyweights Cheick Kongo (26-6-2) and Matt Mitrione (5-0) face off with the winner emerging as a top-10 contender in the division.

Mitrione is the slight favorite, with a money line of -140 while Kongo has odds of +110 to win. Both fighters are primarily strikers, but Mitrione packs the harder punch and is more mobile while Kongo has a slightly better ground game. Mitrione will look to keep the fight standing and stick-and-move while Kongo will look to utilize leg kicks and takedowns to finish the fight with ground-and-pound.

For complete UFC 137 betting odds, check out the jump.

UFC 137 Betting Odds & Fight Card

Saturday, Oct. 29, 2011

Mandalay Bay Events Center, Las Vegas, NV

Welterweight Bout -Nick Diaz (-105) vs. BJ Penn (-125)

Heavyweight Bout- Cheick Kongo (+110) vs. Matt Mitrione (-140)

Heavyweight Bout- Mirko CroCop (+220) vs. Roy Nelson (-280)

Featherweight Bout – George Roop (+265) vs. Hatsu Hioki (-325)

Lightweight Bout – Dennis Siver (+190) vs. Donald Cerrone (-240)

Featherweight Bout – Bart Palaszewski (+240) vs. Tyson Griffin (-300)

Bantamweight Bout- Jeff Curran (+300) vs. Scott Jorgensen (-400)

Light Heavyweight Bout – Brandon Vera (-500) vs. Eliot Marshall (+350)

Lightweight Bout – Danny Downes (+170) vs. Ramsey Nijem (-210)

Middleweight Bout – Francis Carmont (+100) vs. Chris Camozzi (-130)

Middleweight Bout – Clifford Starks (+100) vs. Dustin Jacoby (-130)