Shane Mosley Bet $1 MIL He'd Beat Canelo in 2012, Lost $400K For Fight

Boxing legend Shane Mosley wagered $1,000,000 on himself, betting he'd BEAT Canelo Alvarez in 2012 ... but unfortunately for Sugar, he not only lost the fight, he netted a NEGATIVE $400K in the process!!

The 50-year-old, former multiple-weight class world champion sat down with Mario Lopez for Triller's "OK Bet" show ... and made the stunning admission.

"They were gonna pay me $600,000 [for the Alvarez fight], but I made a bet for a million dollars that I was gonna beat Canelo, and if I would've won I’d have $6 million," Shane recounts.

"I was thinking this snot nose kid is not gonna beat me, you know at 154 (lbs)."

Sadly for Shane's bank account, he was wrong ... and instead of making millions like he would've with a win, he actually LOST hundreds of thousands of George Washington's after paying off his debt.

"I bet a million dollars and I lost so I ended up having to pay back 400,000 dollars. For getting my butt kicked I had to pay $400,000."

If you don't remember the May 2012 fight ... then-40-year-old Mosley took on a 21-year-old Canelo at the MGM in Las Vegas.

Alvarez was 40-0-1 at the time ... and held the lightweight title. But, Mosley, who'd won just 2 of his last 6 fights, and was nearing the end of his great career, believed he still had enough left in the tank to get the W.

After 12 rounds, Mosley ended up losing a 1-sided decision to the future top pound-for-pound fighter in the world ... with 2 judges scoring the bout 119-109, and the other, 118-110.

Shane retired 5 fights later in 2016. Since, the legendary pugilist has been inducted into the International Boxing Hall of Fame.