Sachin dismissed early
Sent into bat first, India were dealt with an early blow when Sachin Tendulkar (4) fell to the bowling of Peter Siddle.
The veteran batsman played a loose shot outside the off-stump and got an edge that went straight to Cameron White at first slip.
India went on to win the match by 99 runs and level the seven-match series.
Image: Sachin Tendulkar walks back to the pavillion after being dismissed for just four runs
Gambhir logs second successive half century
Gambhir joined Sehwag at the fall of Tendulkar's wicket and made his intentions clear. He was tested early on with a couple of snorters but once he hit Siddle for a four, there was no stopping him.
He completed his half-century, his second of the series, off 55 deliveries with a single to third man off Johnson in the 26th over. He looked good for a well-deserved century before he was run-out for 76.
Image: Gautam Gambhir in action against Australia on Wednesday
Dhoni plays sheet-anchor in middle overs
In the middle overs India concentrated on on rotating the strike, with Gambhir collecting 24 singles in his fifty, while Mahendra Singh Dhoni had 21 in his 35.
India's captain scored 124 off just 107 deliveries, hitting nine boundaries and three sixes in the process, as the hosts posted a mammoth 354 for 7 -- their highest total against Australia.
Dhoni's 124 is also the highest score by a captain against the World champions, bettering Sanath Jayasuriya's 122 at Sydney in 2003.
Image: Mahendra Singh Dhoni
Dhoni registers his fifth ODI century
Dhoni completed his century, his fifth in ODIs, in grand style when he slammed Watson straight down the ground for a huge six. It took the right-hander just 94 deliveries to reach the landmark and it included seven boundaries and two sixes.
It also took India past 300 in the 46th over.
The boundaries continued to flow but Australia's brief moment of cheer came in the final over when they claimed three wickets. But, by then, it was too late.
Dhoni was the first to fall in that over when he tried another flick through midwicket but got the outside edge and was taken by wicketkeeper Tim Paine off Johnson. He walked back to a standing ovation from the crowd, after a brilliant knock of 124 from 107 deliveries. He helped the team post what looks like a match-winning total.
Raina's cameo innings of 62 from 50 also came to an end and Praveen Kumar was run-out off the first delivery for 1.
Image: Dhoni acknowledges the crowd after completing his century
Ishant dismisses Watson off his very first delivery
Ishant Sharma struck with his very first delivery, having Watson caught at first slip for 19.
The lanky pacer got one to bounce sharply, and Watson could only guide it to Tendulkar in the lone first slip region. The dismissal left Australia reeling at 41 for two.
Image: Ishant Sharma is ecstatic after taking the wicket of Shane Watson on Thursday
Praveen scalps Ponting
Australia's troubles worsened when captain and batting mainstay Ricky Ponting was dismissed leg before wicket for 12.
Praveen Kumar's incoming delivery did the trick, as Ponting was beaten and struck right in front of the stumps.
Image: Australian captain Ricky Ponting walks off the field after being dismissed by Praveen Kumar
Harbhajan accounts for White
Harbhajan was smashed all over the park by Mike Hussey early in his first spell.
Hussey welcomed him with three consecutive boundaries through the off-side as the off-spinner dropped it short as Australia reached 68 for three after 15 overs.
But he gradually found his footing and compounded Australia's misery when he had White caught at midwicket for 23.
Image: Harbhajan Singh celebrates with Suresh Raina after claiming the wicket of Cameron White