Canelo Álvarez vs. Gennady Golovkin, billed as Supremacy, was a professional boxing match contested for the unified WBA (Super), WBC, IBF, IBO, Ring magazine, and lineal middleweight championship.

The fight was canceled after Álvarez tested positive for a banned substance in March 2018, and formally withdrew pending hearings with the Nevada Athletic Commission in April.

In the end, an agreement was ultimately reached to allow interim bouts before the fight to, in the words of WBC president Mauricio Sulaiman, "maximize the interest in their highly anticipated showdown.

[10] Immediately after his victory over Julio César Chávez Jr. on May 6, 2017, Canelo Álvarez announced that he would next fight Gennady Golovkin on the weekend of September 16, 2017 at a location to be determined.

[14] De La Hoya later also revealed in an interview with ESPN the fight would take place at the full middleweight limit of 160 pounds with no re-hydration clauses, meaning Golovkin and Álvarez would be able to gain an unlimited amount of weight following the weigh in.

[18] Guaranteed Base Purses[19] On fight night, in front of a sold out crowd of 22,358, Álvarez and Golovkin fought to a split draw (113–115, 114–114, 118–110).

ESPN's Dan Rafael and HBO's Harold Lederman scored the fight 116–112 in favor of Golovkin.

Many observers felt that Golovkin had won a narrow, closely contested fight, and while a draw was justifiable, a card that wide in favor of Álvarez was inexcusable.

[20][21][22] Nevertheless, Bob Bennett, director of the Nevada Athletic Commission (NAC), said that he had full confidence on Byrd going forward.

[24][25] The first round found both boxers finding their rhythm, Canelo using footwork to become a slippery target using hard counter shots to the body and head as Golovkin seemed to try to establish his power jab, being the busier of the two.

"[29][30][31] Golovkin's trainer Abel Sanchez believed judge Byrd had her scorecard filled out before the first bell rang.

On September 19, Golden Boy Promotions president Eric Gomez told ESPN that everyone on their side was interested in the rematch and they would hold discussions with Tom Loeffler in the next coming days.

[39] On September 24, Gomez said that the fight would likely take place in the first week of May 2018, but left the possibility of it occurring as early as March.

Golden Boy president Eric Gomez told ESPN that "regardless of if they did or didn't order the rematch, we are going to try to make it happen.

"[41][42] On November 7, Eric Gomez indicated the negotiations were going well and Álvarez would make a decision in regards to the rematch in the coming weeks.

It was believed that Golden Boy would wait until after David Lemieux and Billy Joe Saunders fought for the latter's WBO title on December 16, 2017, before making a decision.

[44] On December 20, Eric Gomez announced that the negotiations were close to being finalized after Álvarez gave Golden Boy the go-ahead to write up the contracts.

[48] Facing a competing bid from New York City's Madison Square Garden, the rematch was booked to once again be held at T-Mobile Arena.

[55] Former two-time light middleweight champion Demetrius Andrade made an offer to fight if Álvarez received a long-term suspension,[56] as well as IBF #1 contender Sergiy Derevyanchenko.

[57] On March 29, 2018, NAC chief Bob Bennett filed a formal doping complaint against Álvarez, which delayed the disciplinary hearing to the commission's next monthly meeting on April 18.

ESPN.com writer Dan Rafael felt that this delay made it more uncertain that the fight would not go ahead, while T-Mobile Arena announced that it would offer full refunds on tickets.

Gomez explained that "given the current regulations in Nevada we have been advised, and it is unfortunate, that Canelo won't be cleared to fight in May.