( CNN ) -- Andre Berto claimed the vacant World Boxing Council welterweight title when he halted Miguel Rodriguez in the seventh round in Memphis . Berto took the WBC belt vacated when Floyd Mayweather retired . Berto ( 22-0 , 19 KOs ) picked up the WBC belt that became vacant when Floyd Mayweather retired . Rodriguez 's record dropped to 29-3 with 23 KOs . Berto floored Rodriguez with an uppercut in the seventh round and when Rodriquez went down a second time referee Lawrance Cole intervened at 2:13 . Dane Mikkel Kessler knocked out Dimitri Sartison in the 12th round in Copenhagen , to become World Boxing Association supermiddle champion . Kessler ( 40-1 ) dominated throughout in front of an enthusiastic home crowd at the Brondby Hall . Sartison , who was born in Kazhakstan but grew up in Germany , suffered his first loss after a 22-0 start in his pro career . Kessler won the WBA title in November 2004 by stopping Manny Siaca of Puerto Rico . He also lifted the the WBC super middleweight crown two years later when he knocked out Markus Beyer of Germany in the third round . But he surrendered both belts when Joe Calzaghe of Wales ended his unbeaten run in Cardiff last November . Britain 's Amir Khan was floored before successfully defending his Commonwealth lightweight title with a fifth round stoppage of Michael Gomez in Birmingham . Khan , who has won all 18 of his fights since turning professional after winning a silver medal at the 2004 Athens Olympics , knocked Gomez down in the first round but found himself on the canvas in the second in a brief but rugged contest . Khan said : `` 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 . '' Khan was on target with a powerful right uppercut in the first round and a combination of punches floored Gomez , who retaliated in the second round . A left hook over the top of a jab put Khan down and he had to take a standing count and looked unsteady on his legs for several seconds afterwards . Gomez landed a damaging hook to the ribs in the fourth but early in the fifth Khan put his opponent down again with a powerful body shot . Gomez began to take a lot of punishment and referee John Keane stopped the contest . Gomez looked disappointed but appeared to be all but out on his feet .
Andre Berto wins the vacant world welterweight title . He halts Miguel Torres in seven rounds . Jason Johnson becomes WBA super - middleweight champion . Amir Khan successfully defends the Commonwealth lightweight title .