Wellington,  A brilliant 216-run opening-wicket partnership between Alyssa Healy (129 from 107 balls) and Rachael Haynes (85 from 100) helped power Australia to a mammoth 305/3 in their rain-reduced ICC Women's World Cup semifinal clash against the West Indies at Basin Reserve here on Wednesday.

With the match being reduced to 45 overs a side, Healy and Haynes scored at an astonishing rate after being sent in to bat first, and put on the third-highest opening stand in Australia's Women's One-day International history.

Their fearless batting was aided by some poor West Indies bowling and an even mediocre fielding. Healy took time to adjust to the overcast conditions and at the end of Australia's opening nine-over powerplay period, the team had put on just 37 on the board.

But it didn't take long for the opener to find her rhythm as she overtook Haynes and then went from 50 to 100 in just 28 deliveries to bring up the fourth ODI century of her career. Healy found the boundary 17 times during her innings and even managed to clear the rope with a huge hit over mid-on from a Karishma Ramharack full toss that pushed her score into the 90s.

Haynes was more circumspect during her stay and was given a pair of lives off the bowling of the unlucky Ramharack, with the usually reliable Hayley Matthews dropping a sitter at mid-on when Australia were on 141.

Shamilia Connell (1/45) finally made the breakthrough when she had Healy caught in the deep in the 33rd over, as the attention turned to Haynes to see if she could reach her own three figure milestone. Chinelle Henry (2/51) made sure she didn't and the West Indies seamer also picked up Ash Gardner -- promoted up the order to No. 3 -- in the same over to help reduce Australia to 236/3.

But Beth Mooney (43 not out) and Meg Lanning (26 not out) combined to push the score past 300 and leave West Indies with a mountain to climb against a formidable Australian bowling line-up. With star all-rounder Ellyse Perry missing through injury, Australia named the same XI that defeated Bangladesh by five wickets in the final group game last week.

West Indies made one change to their side, with Anisa Mohammed coming into the XI for Afy Fletcher.

Brief scores: Australia 305/3 in 45 overs (Rachael Haynes 85, Alyssa Healy 129, Meg Lanning 26 not out, Beth Mooney 43 not out; Chinelle Henry 2/51) vs West Indies.