Australia knocked hosts the West Indies out of the World Twenty20 and kept alive the possibility of an Anglo-Australian final with a dominating six-wicket win here on Tuesday.
West Indies, in a match they had to win by 24 runs to reach the semifinals were bowled out for just 105 at the Beausejour Stadium.
Australia, in reply, lost two wickets on 31.
But Brad Haddin (42) saw Australia to the verge of victory before he got out with two runs needed to West Indies captain Chris Gayle.
The occasional off-spinner then ended the match with a ball that went for five wides, a delivery that summed up his team's performance on the day.
Australia, who finished on 109 for four, won with 22 balls to spare.
Their win ensured Sri Lanka, last year's losing finalists, also went through to the semifinals as Group F runners-up.
England will play Sri Lanka, who earlier Tuesday knocked out India with a five-wicket win, in the first semifinal here on Thursday.
The second semifinal will see Australia playing defending champions Pakistan, also at Beausejour, on Friday.
The final takes place at Barbados's Kensington Oval on Sunday.
Victory meant Australia remained unbeaten at the tournament and captain Michael Clarke said: "Hopefully we can come out and continue this momentum.
"We want to play positive, aggressive cricket, and our fielding standards have been high."
Gayle added: "We lost too many wickets at the top. Australia are playing good cricket. I wish them all the best."
West Indies, who saw Gayle win the toss, suffered a dramatic collapse.
From the relative safety of 52 for two, they lost their next five wickets for 25 runs as they slumped to 77 for five.
Only Ramnaresh Sarwan (26) and Shivnarine Chanderpaul (24) made it past 20.
Australia leg-spinner Steven Smith, the man-of-the-match, took two wickets in two balls on his way to figures of three wickets for 20 runs as West Indies failed to sparkle under the Beausejour floodlights.
West Indies' star batsman Gayle was out second ball, clean bowled by left-arm quick Dirk Nannes, the tournament's leading wicket-taker.
Then the experienced Chanderpaul, having flicked Mitchell Johnson's second and fifth balls for four was out to the left-arm quick's sixth.
The left-handed batsman launched Johnson high over the bowler's head but didn't quite time his shot and David Hussey, running back from mid-on, took a superbly judged catch.
The slump really took hold in unlucky fashion when all-rounder Dwayne Bravo (six) was run out, backing up, after Johnson touched a Sarwan drive onto the stumps at the bowler's end.
Smith then got in on the act as recalled batsman Narsingh Deonarine holed out for a duck, caught by Michael Hussey at deep midwicket.
And he followed up with two wickets in two balls.
Kieron Pollard (13) tried to work the ball legside but was beaten by the turn and wicketkeeper Haddin completed a neat stumping.
Next ball Darren Sammy, in front of his St Lucia home crowd, chipped a simple return catch back to Smith. Jerome Taylor survived the hattrick.
Sarwan, the last of the specialist batsmen, tried to clear long-off but simply holed out off part-time spinner David Hussey to David Warner.
In reply, Warner made a typically brisk 25 off 12 balls before he edged paceman Taylor to Gayle at slip.
And next ball 31 for one became 31 for two when Watson gloved an intended sweep off left-arm spinner Benn onto his stumps.
Clarke helped Haddin add 47 for the third wicket before he was brilliantly run out by Bravo, after an athletic stop and direct hit from short third man.
But that was an all too rare highlight for the West Indies.
SCORES IN BRIEF
WEST INDIES: 105 all out in 19 overs (Chanderpaul 24, Sarwan 26, Smith 3-20, Johnson 2-23, D Hussey 2-3)
AUSTRALIA: 109 for 4 in 16.2 overs (Warner 25, Haddin 42, Clarke 16, D Hussey 10)
Result: Australia won by six wickets.
Man-of-the-match: Steven Smith.