Twelve months of steadily simmering acrimony reaches boiling point here Saturday when world middleweight king Gennady Golovkin faces off against Saul "Canelo" Alvarez in their long-awaited Las Vegas rematch.
We then break down the main event below in BTSport.com's big fight preview, which also includes the best of our huge collection of exclusive build-up video content. "But who knows? Every fight is different.
I have motivation", he said. "But I'm going in there to knock him out".
That is because after the fighters weighed in Friday at T-Mobile Arena before a weigh-in capacity crowd of about 9,000, there was still no faceoff.
The Golovkin camp has been relentless in chastising Alvarez for the failed test and postponement of the rematch.
"Everywhere, biceps, stomach, pretty much all over his body you could see injection marks".
Byrd only gave Golovkin the fourth and seventh round of the fight. "Like a real war". Many at ringside thought he won that bout, but Alvarez pulled off a draw by winning the late rounds as the 36-year-old Golovkin seemed to fade. But it was a tough, competitive matchup that delivered in other ways even without a victor at the end. "The first fight was a good experience".
The 2004 Olympic silver medallist, (38-0-1, 34 knockouts), has repeatedly accused his Mexican opponent of doping, raising the temperature in Las Vegas this week by voicing his suspicions again.
The fight, which carries a pay-per-view price tag of $84.95, is big for the careers of both men.
Members of both entourages quickly got between the two fighters to head off a physical confrontation after Alvarez appeared to rush towards Golovkin, who didn't flinch.
The Mexican boxing star was given a surprisingly short six month ban from the Nevada State Athletic Commission which allows the rematch to take place this weekend.
Abel Sanchez, who has trained Golovkin at his gym in the San Bernardino Mountains outside Los Angeles since 2011, agrees.
In what is already being billed as a potential fight of the century, both Golovkin and Alvarez have been extremely vocal in the build-up to the clash about the other fighter, as well as how they see the fight planning out. "In order to win a fight you have to want to win a fight". A more stationary Alvarez, of course, would make him easier to hit, but Alvarez is more comfortable as a boxer and counter puncher and used those skills to his advantage in the first fight.