Geelong prospect Peake's 109 off 117 balls proved the keystone of the defending champions' win at the Harare Sports Club but he was quicker to praise his bowlers holding their nerve as the Windies gave his unbeaten side a real scare before succumbing by 22 runs.
Peake's ton guided Australia to a formidable 7-314 after they'd been put in on Wednesday, but after a ferocious early Windies counter-attack in reply, the skipper had to rely on paceman Charlie Lachmund and left-arm spinner Aryan Sharma to seal the deal in a nervy finish.
Sharma, who'd earlier dropped a sitter, made amends with a crucial and nerveless catch in the deep off Lachmund in the 48th over before taking two wickets in two balls himself in the penultimate over to seal the deal.
Lachmund, Australia's spearhead whose radar was off earlier as he got hammered around by the brilliant burly Windies opener Zachary Carter, stayed cool when it mattered, taking another wicket in the final over to finish with 4-66 off his nine overs.
It was by far from Australia's best performance on the slower surface in Harare after they'd reeled off four scintillating wins on the seamer-friendly pitch at Windhoek.
Their victories in Namibia had been so easy that Peake hadn't really had chance to demonstrate the sort of brilliance he'd been showing in the BBL before he flew out to Africa, including one spectacular knock for the Melbourne Renegades three weeks ago when he hit a six off the final ball to beat the new champion Scorchers.Â
Peake made up for it, though, once Australia had been given another flying start from leftie Will Malajczuk, who plundered 48 off 30 balls, while his ever reliable opening partner Nitesh Samuel played anchor, with 56 off 74.
Watched by his parents, grandparents and brother in the crowd, Peake then controlled affairs, hitting nine fours and one towering six over long on that took him to three figures off 113 balls, while also gaining valuable support from wicketkeeper Alex Lee Young (45 off 47) and Jayden Draper (29 off 23).
"It's always great to contribute. I haven't had much to do so far - the boys at the top have been doing it all," smiled the 19-year-old skipper.
Asked whether he was exhausted after his recent exploits in the BBL, Peake smiled: "Not yet, there's still bit more to give. It's been a whirlwind two years but your'e always trying to win games, so it would have meant nothing if we'd lost today."
Resting their other star quicks Will Byrom and Kasey Barton, Australia struggled to adapt to the new conditions with the ball to start with, as the West Indies batters tucked in, racing to 1-123 off 15 overs.
But debutant legspinner Naden Cooray struck with his first ball to bowl the rampant Carter (64 off 42) before bowling a terrific 10-over spell for 38 runs that helped check their progress.
Paceman Hayden Schiller (2-54) also made key breakthroughs, while Sharma's 2-47 was decisive, especially when he got rid of the Windies last real dangerman Jonathan van Lange in the penultimate over, caught in the deep.
Australia are now guaranteed to win their Super Six group and will play next week's semi-final in Zimbabwe against the runners-up of the other group, which will probably be either England or India.
