He blazed Tye to the long off rope to finish 84 not out from 46 balls and lift Sri Lanka to 176-8 to secure the series win with a match to spare.
Having lost their first Twenty20 clash against Sri Lanka at the Melbourne Cricket Ground (MCG), Australia looked to redeem itself against the visitors in the second Twenty20 worldwide clash at Kardinia Park in Geelong on Sunday evening.
The Sri Lankans remain unbeaten in five T20Is in Australia, but this was their finest come-from-behind performance in front of their excited expatriate fans.
Earlier, skipper Aaron Finch (43) and Michael Klinger (38) powered Australia to 168-6.
Gunaratne described the win as a very happy moment for him and side after being declared man of the match. The venue made its worldwide debut on Sunday with the women's T20I match between Australia and New Zealand that was played before the men's game.
Back for his first T20 worldwide in more than two years, Dunk threatened to take the game away from Sri Lanka but was a deceived by a slower ball from Gunaratne for 32 from 14 balls. We have beaten South Africa and Australia - one of the best teams in the world - and it is a good feeling.
Lasith Malinga was the pick of the bowlers with two wickets, while Sandakan, Gunaratne and debutant Vikum Sanjaya chipped in with one wicket apiece.
Henriques brought up his maiden T20 fifty in 33 balls with two fours and two maximums. He finished with four for 31 from four overs.
Dilshan Munaweera's one over cost 22 runs, with Dunk clouting him for three sixes and a four.
A Sri Lanka victory seemed unlikely for a large portion of the chase, because by the end of the fifth over they were reduced to 5 for 41.
Even Henriques' 56 not out from 37 balls was somewhat scratchy, given he was dropped in the deep by Kapugedera on 19. Two balls later, Turner dismissed Siriwardana to derail the chase for the visitors.
Earlier, Australia's under-strength attack had torn through the Sri Lankan top order as paceman Jhye Richardson impressed on debut and Andrew Tye was on a hat-trick. Australia surprisingly elected to leave out spinner Adam Zampa despite his strong showing in Melbourne and the success of tweakers during the women's global on the same pitch earlier on Sunday. On Friday, February 17, a second string Australian side will take on Sri Lanka at the Melbourne Cricket Ground (MCG) in Melbourne.
What next for Tamil Nadu and Edappadi Palaniswami
Protesters hurled chairs, tore off documents in demand for a secret ballot, disturbing the decorum and discipline of the House. This was the aftermath of the speaker refusing a secret ballot and then ordering a voice vote for the motion.