At Sydney today, Australia won the first T-20 cricket match against India by 31 runs. Chasing a victory target of 172, the visitors finished with 140 for six in the stipulated twenty overs. Skipper Mahendra Singh Dhoni was the top-scorer with an unbeaten 48, off 43 balls. Earlier, put in to bat, the hosts made171 for four in their twenty overs. The second match of the two-match T-20 series will be played in Melbourne on Friday.