Saul 'Canelo' Alvarez retained his WBC middleweight title after a sixth-round knockout against Amir Khan in Las Vegas on Saturday.

Alvarez, 25, landed a brutal combination to Khan's midriff before a frightening right-hand punch knocked the Brit out cold a minute into the round.

Khan was out before hitting the canvas hard, but after a few concerning moments was able to return to his feet following treatment.

"He’s a fast fighter but I knew time would come to my favour and you saw that," Alvarez said after the fight.

Khan was jumping two weight classes to challenge Alvarez, having never fought about welterweight previously.

The 29-year-old held up against his Mexican opponent early, but Alvarez proved too strong as the bout went on.

The defining moment came in the sixth round when Alvarez landed a brutal right hand, showing the power difference between the two boxers.

"It was hard to turn down this fight but I will probably be going down in weight again," Khan admitted afterwards.

Alvarez is now 47-1-1 with 33 knockouts, while Khan is 31-4.