After Carlos Brathwaite turned it around with a 27-ball 33 (3x4, 2x6), Sammy played the sheet anchor role with an unbeaten 50 laced with one six and six fours to steer them home with a ball to spare.
The win was all the more important as the big-hitting opener Chris Gayle did not bat despite being in the playing XI and they were staring down the barrel after Hazlewood reduced them to 18/3 in the 4th over with his hattrick in their chase of 162.
But Delhi Daredevils recruit Brathwaite, who was snapped up for Rs 4.20 crore in the IPL, displayed his batting prowess taking the attack on Aussie camp with his big hits especially against Mitch Marsh in the 15th over that yielded 17.
He got out in the next over but by then the team needed just 37 from 27 balls and Sammy, the Windies 2012 World Twenty20 winning skipper, completed the formality holding on at the other end.
More From This Section
The duo shared 76 for the opening wicket before Sulieman Benn gave the first breakthrough dismissing Finch as at the midway stage Australia were 85/1.
But the Windies pegged Aussies back riding on Dwayen Bravo's 4/21, while Benn returned with an equally impressive 3/37 as it was their bowling effort that lifted the side at a time when their fielding was once again sloppy.
Having come here short on match practice, it was a morale boosting win for the Windies, who lost their first warmup match to India on March 10, as Sammy danced on his way to scoring the winning run.
Brief Scores:
Australia 161/9 in 20 overs (Shane Watson 60, Steve Smith 36, Aaron Finch 30; Dwayne Bravo 4/21, Sulieman Benn 3/37)
West Indies 162/7 in 19.5 overs (Darren Sammy 50 not out, Carlos Brathwaite 33; Josh Hazlewood 3/13, Andrew Tye 2/35).