Most fans and analysts watching live or at home scored the bout in favor of Gennady Golovkin, so it came as a huge shock when it was announced that judge Adelaide Byrd had turned in a scorecard of 118-110 in favor of Canelo Alvarez.
A more aggressive approach from Alvarez, however, may well play into Golovkin's hands.
Canelo vs GGG 2 Main Event Start Time - Can I watch it online?
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.
Kazakh fighter Golovkin, the defending WBA, WBC and IBO champion, weighed in slightly heavier at 159.6 pounds (72.4 kgs).
Armed with an iron chin, he will be hoping to add Canelo's name to the list of fighters he has felled inside the distance by inflicting the first knockout defeat of his rival's career.
"These stories about contaminated meat are nonsense", Golovkin said, claiming to have seen injection marks on Alvarez's body in photos of his opponent. "I know it's going to be a tough fight".
The most popular fighter in his native Mexico, Alvarez has taken a hit from some of his rabid fans both for testing positive and for not fighting more aggressively. He can only talk about the doping that got him suspended for six months by Nevada boxing authorities, but he can do something in the ring to alter the perception that his style is too conservative. "In order to win a fight you have to want to win a fight".
A bout that was a thriller first time round.
Their eagerly-anticipated showdown will be held at the same venue as their controversial split draw was last September, the T-Mobile Arena in Las Vegas, Nevada. The rematch is sold out, but a lackluster promotion might make it more hard to sell as many pay-per-views as the two fighters did when they first met.