Kelly first called play-by-play of USC football and men's basketball games in 1961 and he was mike side on Trojan games almost yearly until 2003. He did so on radio from 1961 to 1965 and 1973 to 1988, then on TV from 1989 until 2003. He described the action of five USC national championship football teams, five Heisman Trophy winners and 92 first team All-American footballers.