British world champion Paulie Malignaggi retains his WBA light-welterweight title . The 23-year-old Khan stops American Khan in the fourth round . I knew in the last few rounds I was hurting him and all I had to do was put the pressure on him . '' Madison Square Garden fight marked Amir Khan 's big-fight debut on American soil .
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 .