By Ryan Maquiñana, Rick Reeno and Ernest Gabion at ringside

Mandalay Bay in Las Vegas, Nevada - Amir Khan (26-1, 18KOs) knocked out Zab Judah (41-7, 28KOs) in the fifth round to unify the WBA and IBF junior welterweight titles.

Khan established his jab as the range finder in the first round. Neither boxer put forth a workman-like effort in the first three minutes. It was more of a feeling out process by both. Judah displayed some very fast reflexes in the second round, making Khan miss a lot of his punches. During the final thirty seconds of the second, Khan began to find his target and Judah was bleeding from the mouth. At the start of the third, Judah was starting to connect with some very well timed counters. Khan went right back to his jab and the follow-up punches were once again landing. The right side of Judah's face was swelling up at this point, from an earlier clash of heads.

The fourth round showed a lot of defense by Judah. He was ducking and slipping many of Khan's punches, but not throwing any counters in return. Judah started to take some chances in the fith, but he wasn't able to connect and Khan was outworking him. During the round, it appeared that Judah got hit with a low blow and he fell down to his knees. The referee did not see the shot and scored it as a knockdown. He counted Judah out and Khan was credited with a knockout win.