Tonight at 9 pm EDT on HBO pay-per-view, Julio Cesar Chavez Jr faces Sergio Martinez in one of the biggest and most heated fights of 2012. We'll have live round-by-round coverage of all five pay-per-view fights.

We will also have simultaneous live coverage of the Canelo vs Lopez card on Showtime, also beginning at 9 pm EDT. For those wondering, Top Rank will indeed have a live streaming PPV online, which can be purchased at Top Rank TV for $49.95.

Chavez Jr vs Martinez Previews
Big Fight Stories w/Jenny Lewis
Staff Picks / Al Bernstein

Chavez (46-0-1, 32 KO) and Martinez (49-2-2, 28 KO) have had an intense build to this fight, which many thought would never happen, but in the end, got done with pretty much no headaches. Now we've arrived at fight time, and either Chavez Jr is going to prove he belongs with the top fighters in the world, or Martinez is going to prove that Julio can't hang here. There are a lot of factors -- physical and mental -- that could play a big role.

On the undercard, Guillermo Rigondeaux (10-0, 8 KO) will defend his WBA super bantamweight title against Robert Marroquin (22-1, 15 KO) in a 12-round bout; the vacant WBO super featherweight title will be decided between Puerto Rico's Roman "Rocky" Martinez (25-1-1, 16 KO) and Mexico's Miguel Beltran Jr (27-1, 17 KO) over 12 rounds; middleweight contender Matthew Macklin (28-4, 19 KO) looks to bounce back against Joachm Alcine (33-2-1, 19 KO) in a 10-round bout; and in an unusual move, Notre Dame graduate and Subway spokesman Mike Lee (10-0, 6 KO) will face Paul Harnes (4-3-1, 3 KO) in a four-round light heavyweight bout to open the show.

If you've missed anything in the build-up to this fight, check out the pre-fight coverage links after the jump.

• HBO 24/7 Full Episodes: #1 / #2
• Chavez Jr vs Martinez Preview: Big Fight Stories and the Sounds of Jenny Lewis
• Chavez Jr vs Martinez Staff Picks and Predictions
• Al Bernstein's Keys to Victory
• Weigh-In: Video / Results
• Naazim Richardson in Vegas with Team Martinez
• Betting Odds and Preview
• Full Fight Video: Chavez Jr vs Lee
• Full Fight Video: Martinez vs Pavlik
• Judges, Referee Named
• Final Press Conference Quotes
• Video Preview: Sergio's Rise to the Top
• Video Preview: Julio Cesar Chavez Jr & Freddie Roach
• Video Preview: The Matchup and Sergio's Stolen Title
• Video Preview: The Fight
• Purses: JCC Jr $3 Million, Sergio $1.4 Million