Gabriel Rosado during his war in the ring with Gennady Golovkin
Floyd Mayweather will be the star of the show on May 4 when he faces Robert Guerrero at the MGM Grand in Las Vegas, but recent developments in the undercard could compete for attention.
From an action-packed rematch sure to enter the pantheon of classic Puerto Rico vs. Mexico wars to an all-Mexican world championship featherweight battle, this undercard is stacked with bloody action.
Here is a fight-by-fight look at the televised undercard.
Gabriel Rosado and Alfredo Angulo had a short but fierce two-round firecracker of a fight that ended in brutal fashion with Angulo knocking out Rosado.
Boxing Scene reports that their rematch is in the works for the Mayweather-Guerrero undercard.
In the four years since the first fight, Angulo has been knocked out in six rounds by James Kirkland, and Rosado lost a brutal war to Gennady Golovkin after building a knockout winning streak to earn the shot.
Now both fighters will be coming into the ring with something to prove and a history of throwing every ounce of effort into every punch.
Daniel Ponce De Leon, the current WBC featherweight world champion, will defend his title against undefeated former WBC super bantamweight world titlist Abner Mares.
Boxing Scene reports confirm this match will take place on the Mayweather vs. Guerrero undercard with manager Frank Espinoza calling it a potential show-stealer.
Ponce De Leon's won by knockout in 35 of 44 wins. While Mares has netted 13 knockouts in 26 fights, but he fights every second of every minute he's in the ring. Expect a bloody encounter with this one.
Leo Santa Cruz delivering a punishing bodyshot uppercut to Eric Morel.
In today's boxing landscape, pay-per-views traditionally have one main event and three other fights on the televised undercard. Mayweather vs. Guerrero obviously fulfills the main event.
With Ponce De Leon vs. Mares and Rosado vs. Angulo II coming together, that leaves only one spot. The problem is that there are two fighters in two vastly different weight classes rumored to take that slot.
Fight Hype reports that undefeated Mexican IBF bantamweight world champion Leo Santa Cruz will fight on the undercard against an opponent to be determined.
For a few months, undefeated American WBC lightweight world champion Adrien Broner has been rumored to appear on the undercard.
The deciding factor could be the network broadcasting the fight. Mayweather vs. Guerrero is the first of Mayweather's six-fight deal with Showtime/CBS. Broner, though not under contract, has been very loyal to HBO.
This makes the appearance of Leo Santa Cruz more likely than the appearance of Broner. Either way, both would make an excellent addition to what is already a great show.