The diminutive southpaw timed his unbeaten run-a-ball century in the rain-abandoned second Commonwealth Bank Series match in Brisbane to absolute perfection with his score ticking through to three figures in the final deliveries.
Gambhir arrived at the crease at the loss of Sachin Tendulkar in the 15th over and batted cautiously in the beginning before opening his arms in an unbroken 184-run stand with skipper MS Dhoni.
"Getting a hundred is always a great feeling, especially when you get a hundred in Australia because of the conditions," the Delhi skipper, who led his side to Ranji Trophy title, said afterwards.
Following Sri Lankan wicketkeeper Kumar Sangakkara's grounding of a regulation chance with Gambhir on just 11, he finished an exciting innings one run short of his highest international one-day score after crashing paceman Lasith Malinga for two boundaries in the final over.
Sri Lanka's reply never got started as the Gabba was deluged for the second evening in three days.
Gambhir, whose approach to the spinners has frequently been questioned in India, conceded that Muttiah Muralitharan was 'all over me' in their opening exchanges and that he found it impossible picking the off-spinning magician.
Murali dismissed Yuvraj Singh for two and Rohit Sharma for a duck in his opening five deliveries while Gambhir watched from the non-striker's end.
But the one-day regular, who was recently recalled to the Indian Test side after a two-year absence, visibly grew in confidence and said he hoped his third ODI ton would end speculation over his place in the side.
"You love to perform in conditions like Australia because it gives you a lot of satisfaction as a player," he said. "The conditions are not like in India and so there are always question marks over your technique."
"But once you start getting runs in Australia, you know that you've got enough in you to stay at this level."
"That is what I feel about this innings. It's given me a lot of confidence."
Gambhir also maintained the whole Indian setup would take plenty of belief to Melbourne where they meet the hosts on Sunday despite starting the triangular series with a pair of no results.
"We had a very good chance of beating Australia in the first game … and today we also had a very good chance because we had a very good total on the board," he said.
"I personally feel we were a bit unfortunate because we could have won both games."