Tuesday 13 June 2017 14:47, UK
After a controversial decision concluded the thrilling first clash, Andre Ward will again face Sergey Kovalev for the WBA, WBO and IBF light-heavyweight titles in a much-anticipated rematch, billed 'no excuses'.
When the pair battled for pound-for-pound glory the first time round it was Kovalev, the devastating puncher, against Ward, the master technician.
Ward got the verdict over his Russian foe, a narrow unanimous decision, but it was a result disputed by many and now the score will be settled when the pair meet in the early hours of Sunday morning live on Sky Sports, again from Las Vegas.
Ahead of Sunday's mega showdown, we look at five other disputed decisions that meant a rematch was needed to finally find a conclusive result…
Despite retiring with an unblemished record of 49-0 and a career of almost indisputable domination, it has not always been as comfortable as the history books might suggest for pound-for-pound great Floyd Mayweather Jr.
In 2002, having dominated the super-featherweight division, 'Money' moved up to lightweight to challenge Mexican Jose Luis Castillo for the WBC belt.
Castillo managed to lure his flashy, younger opponent into a toe-to-toe battle, his relentless power seeming to turn the fight in his favour through the middle rounds before convincingly ending the fight the stronger of the two.
Despite this, Mayweather Jr got the verdict on all three judges' scorecards, a decision that was loudly booed by those in attendance. Months later, the rematch was signed.
The Las Vegas-based champion came into the return fight following successful shoulder surgery and this time there was no argument over the result. 'Money' was slick, quick and intelligent in coasting to another unanimous decision.
Lennox Lewis faced American Evander Holyfield in a blockbuster unification clash in 1999 with the WBA, WBC, IBF and lineal world titles on the line.
It was the Brit who seemed to dominate the fight, working behind a lengthy jab, peppering his foe with combinations and almost constantly out-landing his opponent throughout the heavyweight bout.
Lewis had clearly won the fight, or so it was assumed, before the judges' scorecards resulted in a draw, with many quick to call the decision a "travesty".
Unsurprisingly, almost immediately after the fight, a rematch was ordered and the return bout took place eight months later. Again, Lewis did the better work and this time, he got his just rewards and became the undisputed heavyweight champion of the world with a unanimous points verdict.
Eight-division world champion Manny Pacquiao went into his fight with Timothy Bradley on a fine run of form, having previously beaten Antonio Margarito and Shane Mosley before narrowly edging out Juan Manuel Marquez.
Bradley was unbeaten and had unified world titles at super-lightweight, but the step up to welterweight to face someone of Pacquiao's stature was widely considered to be a step too far.
Despite this, Bradley won a split decision, albeit a highly controversial one. 'Pacman' seemed to land the harder punches, taking control early, beating Bradley on most exchanges and countering well. The judges sat ringside disagreed.
Two years later in 2014, Pacquiao finally got the opportunity to take revenge and this time the Filipino left the result in no doubt. He would go on to comfortably win a rubber match in 2016, knocking Bradley down twice on the way to a points win.
Carl Froch and Mikkel Kessler first fought in April, 2010, as part of the Super-Middleweight Super Six tournament, Froch having beaten Andre Dirrell in his first bout while Kessler had lost to Andre Ward.
The championship bout, which took place in Denmark, Kessler's hometown, was closely contested, both boxers having great moments throughout what was a fight-of-the-year contender.
After a brutal encounter, the scores read 116-12, 115-113 and 117-111 in favour of Kessler, who took Froch's WBC title having inflicted the first professional defeat on the Brit. Many felt the fight was much closer than the scorecards suggested.
Three years later, the pair would meet again in London, IBF champion Froch seeking to dethrone WBA titlist Kessler in a unification clash. This time, Froch earned a unanimous victory. Despite the Brit levelling up the score, a much sought-after rubber match never materialised.
Former unified world champion Tyson Fury, currently undertaking an enforced layoff from the sport, remains undefeated in the professional ranks, but like Floyd Mayweather Jr, many feel he should have a loss on his unblemished record.
Fury, the self-proclaimed 'Gypsy King', came close to defeat in just his eighth fight as a professional, his first title fight, as he faced tough stalwart John McDermott for the English heavyweight title in 2009.
Referee Terry O'Connor scored the fight 98-92 in favour of Fury, much to the bemusement of those watching both at home and ringside, some even claiming that O'Connor got the names mixed up.
The common consensus was that McDermott won fairly comfortably. The necessary rematch took place a year later and this time there was no controversy as Fury improved on his first performance to win via a ninth-round stoppage.
Paul Smith vs Tyron Zeuge is live on Sky Sports 1 HD from 9pm on Saturday, then Andre Ward vs Sergey Kovalev II is live on Sky Sports 1 HD from 2am on Sunday morning.
