Amir Khan got up from a second-round knockdown and stopped Michael Gomez in the fifth Saturday, successfully defending his Commonwealth lightweight title for a fourth time. Khan knocked down Gomez twice, first in the opening round and again early in the fifth, before a huge right hand forced the former British super featherweight champion against the ropes for a final flurry – when referee John Keane stepped in to halt the fight 2:32 into round. The victory kept the Olympic silver medalist unbeaten in 18 bouts as a pro and bolstered his stated desire for a title opportunity against WBO champion Nate Campbell next year. Gomez lost for the fourth time in his last seven fights, and dropped him to 35-9 on his 31st birthday. Khan tagged Gomez with a sharp left jab in the opening round and followed with a torrent of punches, finally dropping him with a big right. After surviving the round, Gomez raced out for the second, and – having stormed through Khan's sharp blows – hit Khan's jaw with a left hook which briefly dropped him. However, Khan quickly regrouped and again used his left to put Gomez back in trouble. Khan agreed he'd made errors on the way to his latest victory, telling ITV: “I got caught with a left hook and I dropped my hands but I didn't make that same mistake again. “It was one of those flash knockdowns but I got straight back up. “This was one of my toughest fights but I learned from my mistakes. I will watch the video and work on them and continue my journey to the world title.” Despite developing a cut around his left eye, Gomez plowed forward in search of another knockdown. The two exchanged left hooks to close a furious second round, and into the third, Khan continued to connect with his right as Gomez repeatedly moved forward with his head down to regain the initiative. Khan landed several hard punches in the fourth that hurt Gomez but couldn't knock him off his feet, and Gomez recovered sufficiently to respond with blows of his own. Khan dropped Gomez early in the fifth with a left to the body, but once more Gomez got to his feet to land a straight left that caught Khan, but without much force. A jolting right midway through the fifth knocked Gomez back against the ropes one last time, and as Khan repeatedly battered him with both hands, Keane wisely decided to end the bout. Kessler KOs Sartison In Denmark, Mikkel Kessler knocked out Dimitri Sartison in the 12th round to capture the vacant World Boxing Association supermiddle title early Sunday morning. Kessler (40-1), dominated the bout from the beginning before a roaring home crowd at the Brondby Hall on the outskirts of the Danish capital of Copenhagen. For Sartison, who was born in Kazhakstan but grew up in Germany, it was the first loss after a promising 22-0 start of his pro career. Berto stops Rodriguez In Tennesee, American Andre Berto claimed the WBC's welterweight title with a technical knockout of Mexican Miguel ‘Mikki' Rodriguez on Saturday, seizing the crown only four years and 22 fights into his professional career. Berto stopped Rodriguez in the seventh round to capture the vacant title in his first attempt at a major belt. “I'm really excited right now,” Berto said. “It's an unbelievable feeling at age 24 that I'm now the world champion.” Berto knocked Rodriguez down twice in the seventh before the referee stopped the bout with 47 second left as Berto continually rocked Rodriguez with right hands. The bout became a battle for the belt after former champ Floyd Mayweather Jr. retired earlier this month, setting the stage for Berto and Rodriguez, the top contenders, to fight for the championship.