Khan dominated Judah after five rounds. Reuters

Amir Khan is legit.

Fighting in Las Vegas for only the second time of his career, Khan dominated veteran Zab Judah for five rounds before knocking out out Judah in perhaps controversial fashion on Saturday night.

Khan delivered a right hand that hit Judah on the belt, and Judah went down. The referee counted down Judah, who was on his knees and fists as he complained about a low blow.

Whether Khan delivered a low blow or not is somewhat debateable, but what wasn't debateable was the overwhelming domination that Khan exhibited in the fight. HBO's Harold Lederman scored the fight in every round for Khan.

With his eyes on a future fight with Floyd Mayweather at the welterweight division, Khan showed that he deserves to be rated as one of the best boxers in the sport.

For Judah, it was another disappointing effort. Unless Cory Spinks is considered a prominent boxer, Judah still lacks a win over a top-rated boxer.

It is now up to Khan to find another challenge as he moves up in weight class.