Saunders is receiving hospital treatment for a suspected fractured eye socket after Alvarez caught him with a shuddering punch in the eighth round in Texas.
Saunders’ eye immediately became puffy and swollen and while he fended off an Alvarez barrage for the rest of the round, he didn’t make it back out for the ninth,
Saul Canelo Alvarez said he knew Billy Joe Saunders was hurt by his nasty uppercut
Speaking in the ring immediately after the fight, a jubilant Alvarez said: ‘I said it would be around round eight.
‘I think I broke his cheek and I knew he wasn’t going to come out.
‘I told my corner he’s not coming out because I broke his cheek. I have the best trainer, I prepare. He says do this and I do it.’
Saunders, who went into the fight undefeated, had been tipped to cause Canelo problems and he grew into proceedings as the encounter went on.
But as soon as Canelo caught him in the middle of round eight with a nasty uppercut, his demeanour changed and he looked like a man who knew he was badly hurt.
With the crowd sensing blood, Alvarez went in for the knock-out but Saunders managed to endure the onslaught and make it back to his corner,
But by that point, his eye was swollen and puffy and he was clearly struggling to see.
Speaking in the aftermath, his promoter Eddie Hearn said: ‘He couldn’t see. I spoke with (trainer) Mark Tibbs and he wouldn’t let him go out.
‘Billy boxed beautifully, Canelo busted his eye socket. Canelo came on strong at the end of the fight.’