Deandra Dottin and Hayley Matthews began the chase as aggressively as their hefty target required, but they both fell for 34. By the time captain Stafanie Taylor dug in for a steadying but rather circumspect innings, it was too late.

Australia will play the winner of Thursday's second semi-final between defending champions England and South Africa in the title decider.

Despite a sedate start by Healy, West Indies' bowlers struggled to find their lines and lengths after winning the toss. A rash of fielding mistakes spread from tough chance to squandered gifts as Healy overtook Haynes, to whom she'd played a supporting role initially. Healy's first fifty runs came off 63 balls while her second came from just 28 and she finished with 17 fours and a six.

After the powerplay, reduced to nine overs because of the rain delay, Australia were 37 without loss, although Healy hadn't found the boundary while Haynes looked in fine touch, punishing anything short or overpitched as she picked off four fours en route to 26 from 34 balls.

With four spinners at her disposal, Taylor turned to Matthews in the ninth over and she got her offbreaks turning sharply at the outset, using a patch of green grass outside the right-hander's off stump to find some grip.

Encouraged, Taylor brought on Anisa Mohammed - a replacement for Afy Fletcher, who was out after testing positive for Covid-19 - a short time later and her third legitimate delivery - a full toss - yielded Healy's first four as she cleared mid-on.

With Healy finding her groove, having survived on 5 when Chinelle Henry spilled a difficult return catch, she struck three fours off six balls from Mohammed and Henry, and Karishma Ramharack promptly replaced Mohammed in the attack as West Indies searched for a way to break the union.

Even a return to pace with Dottin failed and both batters brought up their fifties in the same Ramharack over, the 22nd of the innings, before Dottin conceded 18 off her third over in which a gorgeous Haynes pull to the deep midwicket boundary was bookended by fours driven wide of cover and threaded through fine leg by Healy.

Haynes miscued a sweep off Ramharack but was put down by Shamilia Connell at midwicket, and by the time Healy heaved Ramharack over mid-off, a patch of bright sunshine had broken through. But the pall of missed opportunity hung heavy over West Indies when Matthews put down a sitter at mid-on four balls later that would have seen Haynes dismissed for 61.

It got even worse for West Indies as Mohammed, chasing hard to stop another Healy boundary, pulled up with what looked like a serious hamstring injury and had to be driven from the field.

Healy then smacked a Ramharack full toss from about a foot above head height down the ground for a 73m six over long-on and struck the next ball for four back down the ground to move to 98. She brought up her maiden World Cup century - and fourth in ODIs - with a single through cover, with a visceral "yeeeeessss!" as she struck the ball.

Healy was put down again on 123 by substitute fielder Shakera Selman running in from long-on, but she made amends a short time later, diving forwards at mid-off to hold onto a Healy top-edge off Connell and finally give West Indies a wicket in the 33rd over.

Australia plumped for big-hitting finisher Ashleigh Gardner instead of usual No. 3 Meg Lanning but she failed to make and impact and Haynes fell spooning Henry to Dottin at extra cover for 85. Beth Mooney produced a neat cameo of 43 not out off 31 balls, including three consecutive fours off Taylor, as she and Lanning added 68 runs.

Mooney then took a screamer during West Indies' chase, diving to her right at square leg to pluck the ball from the air almost after it had passed her, which left bowler Megan Schutt aghast and Rashada Williams trudging off the field for a duck.

At the end of the powerplay, West Indies were on track at 39 for 1 but Tahlia McGrath entered the attack in the 10th over and struck with her third ball as Dottin holed out to Annabel Sutherland at long-on.

By the time Jess Jonassen removed Matthews, caught by Alana King who had earlier copped a nasty blow to the neck trying to stop a ball flicked soundly by Matthews on the bounce to midwicket, the required run rate was nudging 10 per over. And it crept ever higher as West Indies lost 3 for 8 in 10 balls, including Chedean Nation, run out by none other than Healy, while she was attempting a second run.

Taylor was dropped on 46 by Sutherland off Gardner, although Gardner trapped Ramharack lbw next ball. With the injured Mohammed and an unwell Henry unable to bat, Australia progressed when King had Taylor caught by Jonassen at backward point for 48, sealing a comprehensive victory and a seventh World Cup final berth.