Concussion substitute Yuzvendra Chahal took three crucial wickets as India beat Australia by 11 runs to win the opening T20 at the Manuka Oval in Canberra on Friday.
Chahal came into the side after batting hero Ravindra Jadeja was ruled to have suffered concussion when he was hit on the helmet during his match-turning 44 not out.
Chahal then took the key wickets of Australian captain Aaron Finch, Steve Smith and Matthew Wade as Australia fell short in the run chase.
"Concussion replacements are a strange thing, today it worked for us, maybe another time we wouldn't have found a like-for-like," Indian captain Virat Kohli said after the game.
"He came in and bowled really well. The pitch offered him enough. We showed character to fight back."
The substitution was controversial as Jadeja had earlier suffered an apparent hamstring strain while running between the wickets and went on to score freely after being hit, before being withdrawn between the innings.
But Finch accepted the decision.
"They let us know their doctor had ruled Jadeja out with concussion, and you aren't going to overrule medical advice," Finch said.
Finch earlier won the toss and chose to bat in perfect conditions in Australia's capital city.
Indian opener KL Rahul batted well at the beginning, but the other Indian batsmen struggled to stay with him.
Mitchell Starc, who had been disappointing in the ODI series, struck in his second over when he bowled Indian opener Shikhar Dhawan with a beautiful outswinger to leave the Indians 11 for one.
Rahul began to take control with some powerful hitting, but with the score on 48, captain Kohli fell for just nine when he tamely chipped a Mitchell Swepson short ball back to the bowler, the young leg-spinner taking an easy catch.
Sanju Samson played some big shots on his way to 23 off 15 balls before he hit a Moises Henriques delivery straight to Swepson at mid-off to leave India at 86 for three.
It was soon 90 for four in the 13th over when Manish Pandey got a top edge to leg-spinner Adam Zampa, with Josh Hazlewood taking a sharp catch at short third man.
India were in further trouble when Rahul holed out to Sean Abbott at long-on, leaving them 92 for five at the end of the 14th over.
Any chance India had of getting to a big total seemed to have disappeared when Hardik Pandya was caught at long-off for 16, leaving the visitors 114 for six with only three overs remaining.
But although limping badly after appearing to strain his hamstring on 18, Jadeja smashed the Australian attack to all corners, scoring 30 runs from his final 10 balls to allow his side to post a competitive total.
Finch and fellow opener D'Arcy Short gave Australia a fast start, even though Finch was limping with what appeared to be a leg injury suffered while fielding.
The Australian captain looked in no trouble but on 35 he hit a sky ball to long-off to become Chahal's first victim.
Smith followed soon after for 12, falling to another catch in the deep, this time Samson diving full length at long-on.
"It was a great feeling," Chahal said. "There was no pressure for me when we were batting, then I got to know I was going to play -- 10 to 15 minutes before, I got to know I would play."
When the dangerous Glenn Maxwell departed lbw to T Natarajan on review, Australia were struggling at 75 for three after 11 overs.
None of the remaining Australian batsmen was able to come to terms with the conditions and wickets fell at regular intervals to put India firmly in control.
The two teams meet again in Sydney on Sunday and Tuesday.