The duo took charge of the Australian innings after the Indian bowlers had dismissed opener LJ Poulton in the 14th over and slowly but surely guided their team towards the victory target of 184.
G Sultana finally got rid of Blackwell but KL Rolton and Sthalekar safely achieved the required total without further hiccups.
Except for R Dhar, who claimed one wicket giving away just 17 runs in eight overs, the rest of the Indian bowlers failed to make much of an impact.
Earlier, electing to bat after winning the toss, the Indian eves suffered an early jolt when J Sharma was caught leg before by DM Kimmince in the fourth over.
Indian wickets fell at regular intervals before Jhulan Goswami carried out a late charge, smashing 46 runs off just 41 balls.
However, it was a case of too little too late and was not enough to ensure vicory for India.
The second match of the series will be played tomorrow.