Perry (25 off 22) combined with captain Jodie Fields (36 off 38) in an unbroken stand of 50 off 40 balls, that boosted their side from a parlous position of 7-209, after the Southern Stars lost 4-28.
Drama enveloped Perry even before she bowled her first delivery.
Twice she pulled out before reaching the crease, sending a shiver through Australian supporters, who feared the ankle injury that kept her out of the last two games had not healed.
"From that point I thought it was going to be a pretty long night for me," Perry said.
"I've been really really fortunate. I've had a wonderful support staff looking after me, particularly our medical staff"
Perry quickly dispelled worries about her health with a match-tilting spell .
She trapped Kycia Knight (17 off 35) with the final ball of her first over to end a 32-run opening stand off ten overs.
Off the first ball of her second over, she appeared to have star batter Stafanie Taylor caught in the slips by Meg Lanning, but the third umpire couldn't confirm the ball had carried.
Perry didn't require assistance three balls later when she took a simple return catch to remove Taylor (5 off 9).
The Australian football international struck again in her third over, earning an lbw decision against opener Natasha McLean (13 off 30).
Veteran allrounder Lisa Sthalekar (2-20 off 10) was Australia's other bowling hero.
The clever spinner outfoxed West Indies captain Merrisa Aguilleira (23 off 46) and powerful hitter Deandra Dottin (22 off 28).
Both were looking dangerous, with Dottin smashing two sixes and Aguilleira one, but Sthalekar bowled both to leave West Indies 5-109 in the 31st over.
West Indies quickly slumped to 8-114.
Megan Schutt (2-38 off 10) struck twice to finish he tournament's leading wicket taker with 15.
Schutt, spinner Erin Osborne (2-26 off 7) and opening bowler Julie Hunter (1-18 off 4.1) swept through the bottom half of the order.
"We spoke a lot about coming into this match and having a dominating performance and I think we did that today," Fields said.
"We came out with the bat and we dominated and followed it up with a great fielding and bowling performance.
"What more can you ask for?"
-AAP