LAS VEGAS – Dmitry Bivol didn’t simply accept congratulations in the aftermath of his career-changing upset of Canelo Alvarez on Saturday night.

The unbeaten WBA light heavyweight champion also applauded those that were savvy enough to bet on him in advance of their 12-round, 175-pound title fight at T-Mobile Arena. Mexico’s Alvarez (-550) was more than a 5-1 favorite over Bivol (+400) when the bell rang, according to MGM Grand’s sportsbook.

Alvarez also was widely viewed as boxing’s pound-for-pound king and hadn’t lost in 8½ years. A bigger, busier, sharper Bivol beat him handily, however, to retain his title and establish himself as one of the sport’s elite talents.

The 31-year-old Bivol’s confidence never wavered, not even when Alvarez got off to a strong start that left him ahead by the same score, 40-36, on all three scorecards entering the fifth round. Bivol’s superior conditioning served him well, as he won seven of the final eight rounds on the cards of judges Tim Cheatham, Dave Moretti and Steve Weisfeld.

All three judges scored Bivol the winner by the same score, 115-113. Alvarez lost for the first time since undefeated Floyd Mayweather, then boxing’s biggest star, beat him by majority decision in their 12-round, 154-pound championship match in September 2013 at MGM Grand Garden Arena.

Mayweather revealed on social media late Saturday night that he even placed a $10,000 wager on Bivol to upset Alvarez (https://www.boxingscene.com/mayweather-claims-easy-pick-up-winning-42500-from-bet-on-bivol-over-canelo--166067).

“I have a message for people who bet on me today, you know, who won,” Bivol said during the post-fight press conference. “Congratulations, guys!”

Russia’s Bivol (20-0, 11 KOs) wasn’t offended by bettors who believed Alvarez (57-2-2, 39 KOs) would continue his reign as the sport’s pound-for-pound king.

“But [people] who didn’t believe in me, it’s just their opinion and I appreciate them,” Bivol said. “But they bet on Canelo, they believed in Canelo. It’s normal, you know? It’s normal. It’s no problem.”

Bivol thrived in his role as the underdog in an arena full of Alvarez’s loyal fans who were there to celebrate their beloved boxer on Cinco de Mayo weekend in “The Fight Capital of the World.”

“I know how people love Canelo,” Bivol said. “And it’s normal, you know? He’s really the biggest fighter in the world. He’s a champion for four weight classes. He has four belts [in the super middleweight division]. Of course, all people [are] on his side. No problem for me.”

Alvarez plans to exercise his contractual right to a rematch with Bivol, but it might not happen next.

The 31-year-old Alvarez was vague when asked if he’ll battle Bivol next or move forward with his previously planned third showdown with nemesis Gennadiy Golovkin. Alvarez and the 40-year-old Golovkin had committed to finally fighting a third time September 17 before Bivol disrupted their plan.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.