British world champion Paulie Malignaggi retains his WBA light-welterweight title . The 23-year-old Khan stops American Khan in the fourth round . Madison Square Garden fight marked Amir Khan 's big-fight debut on American soil .
British world champion Amir Khan retains his WBA light-welterweight title . The 23-year-old Khan stops American Paulie Malignaggi in the 11th round . The Madison Square Garden fight marked Khan 's big-fight debut on American soil .