Shane Watson made the second-highest Twenty20 international score of all time but the stand-in Australia captain's heroics were unable to deny India a seven-wicket win off the final ball to seal a series whitewash at the SCG on Sunday.

Watson's international future has been called into question after he was dropped from the one-day international squad to face India, but the all-rounder showed he is not finished yet by smashing a sublime 124 not out from 71 balls.

The 34-year-old opened in the absence of regular skipper Aaron Finch as Australia posted 197-5, but the tourists succeeded in a magnificent run chase to win the series 3-0.

Rohit Sharma (52) and Virat Kohli made (50) made half-centuries yet again and Suresh Raina hit the last ball for four with two needed to finish 49 not out.

T20 international debutant Usman Khawaja (14) was dismissed without making a half-century for the first time since October when he was caught behind off Ashish Nehra (1-32), but Watson led by example at the top of the order.

Watson was given a lifeline when Kohli dropped him on 58 and took full advantage, becoming only the second Australian batsman to score a T20 international century when he took 19 off a 17th over from Ravindra Jadeja.

The brilliant Watson put on 93 with Travis Head (26) for the fourth wicket and reached three figures from only 60 balls, with the carnage continuing as he carried his bat after hitting six sixes and 10 fours in a ferocious display of batting.

Shikhar Dhawan (26) and Rohit got the tourists off to a blistering start in an opening stand of 46 in only 3.2 overs before Watson (1-30) had the former caught behind.

Rohit, fresh from making 60 at the MCG on Friday, passed 1000 T20 international runs in another classy knock to set up the victory, but the impressive Cameron Boyce (2-28) got rid of the opener in the 13th over with 124 on the board.

Australia debutant Cameron Bancroft missed the chance to stump Raina two balls later and that proved costly as, although Boyce struck again to dismiss Kohli, India came out on top once more.

India needed 17 to win from the last over and Raina hit the final ball from Andrew Tye (0-51) to the boundary after Yuvraj Singh had taken 10 off the first two deliveries.