Amir Khan would have loved to tell the world personally what he thought about another painful evening of his intriguing career, because he has never been one to dodge a challenge.

But he had to deliver a second-hand message from hospital on Saturday night to reassure fans and inquiring writers he had recovered fully from a devastating knockout by Saul "Canelo" Alvarez a couple of hours earlier.

No amount of sympathy from well-meaning friends could wash away the pain and disappointment he felt after a nano-second of distraction cost him consciousness and left him in a dazed heap at the Mexican's feat near the end of six tense rounds at the T-Mobile Arena.

"I'm OK, everyone," he said through the promoter, Oscar De La Hoya. "That's boxing for you. Congratulations to Canelo. Much love to all the fans."

De La Hoya was glowing in his praise for the loser, whom he has always admired, declaring he would be back to challenge for world titles, but not at middleweight.

"We took precautionary measures and Amir Khan went to hospital," he said. "He had an evaluation and he's OK."

De La Hoya added: "Amir Khan is one of the bravest fighters on the planet. He didn't lose anything today. He will come back. There is no shame in his performance. He was up on one scorecard and the other two were really close. I had it even. His speed and amateur experience... I didn't expect him to be this fast.

"He's a gifted, disciplined boxer. He got caught with one punch, which was coming at him lightning fast with tons of power.

"Canelo said he was really frustrated in the early rounds, and that is what Amir does to you. I've always said Amir is too brave for his own good. There will not be another middleweight with speed like Amir Khan's."