Australia defeated India by four wickets in the second match of the on-going ODI- Tri-series tournament. At Melbourne today, set to score 268 runs for a win, the hosts surpassed the target by making 269 for 6 in 49 overs.Earlier, electing to bat after winning the toss, India made 267 for 8 in the stipulated 50 overs. Rohit Sharma was the top scorer with a fine 138, which was his sixth ODI Hundred.For Australia, it is their second win, after their three-wicket victory over England in the opening encounter on Friday at Sydney.In the third match of the Tri-Series, India will take on England at Brisbane on Tuesday.