Mexico's undisputed super middleweight world champion Canelo Alvarez promises his title bout with Terence Crawford in Las Vegas on Sept. 13 will be one of the legend's "best."

The 34-year-old became sole possessor of all the title belts at the weight for a second time when he beat IBF champion William Scull by a unanimous points decision in Riyadh last month.

Crawford was at that bout and immediately threw down the gauntlet — gladly accepted by Alvarez — even though it means the 37-year-old American has to step up two weight divisions.