Amir Khan, 29-years-old, stands at a critical juncture in his career following a stinging loss to Saul "Canelo" Alvarez last month, that took his career record to 31 wins and four losses.

A two-time former junior welterweight world champion, Khan stepped up two divisions to fight his brawny middleweight opponent after he was denied a coveted matchup with Floyd Mayweather, who retired last year.

Khan had never fought beyond the welterweight limit of 147-pounds, but agreed to meet the much bigger Canelo at a catch-weight of 155. There was no catch-weight and Canelo was significantly bigger in the fight. Some estimate he was well over 170-pounds. The Mexican star refused to allow HBO to weigh him in the locker room.

He got off to a lightning start, but after dominating the early rounds was caught with a powerful overhand right that put him on the canvas in the sixth. No count was needed as the Bolton fighter was out cold from the shot.

Looking more trim than he appeared during the Last Vegas bout, Khan was sanguine about his loss and insisted he was looking forward to his next world title shot against WBC welterweight champion Danny Garcia. Despite the loss to Canelo, Khan retained his position as the mandatory challenger to Garcia's title.

"I feel great. I feel young, fresh. I mean, the Alvarez fight, everything was going fine until I got caught with the big shot and that's boxing for you sometimes. One punch can change the fight. You can be winning the fight quite comfortably and I've seen it happen to the best of us," Khan said.

"So, I'm gonna go back to the drawing board and not make those mistakes. I know that my offence was amazing in that fight. But maybe tighten up a few little areas."