Hosts Sri Lanka defeated Zimbabwe by 82 runs in the opening match of the Twenty20 World Cup Cricket tournament at Hambantota last night.All India Radio will broadcast live commentary on both the matches today alternately in Hindi and English on the national hook up and additional frequencies. The commentary of the Australia-Ireland encounter will be heard from 3 PM till 6 PM, while the commentary on the India-Afghanistan match will begin from 7 PM till the end of the match.