Australia knocked out hosts West Indies with a comprehensive six-wicket triumph in their final Super Eight match, setting up a semifinal clash against Pakistan in the Twenty20 World Cup at St.Lucia. Set a paltry target of 105, Michael Clarke's men romped home with 3.4 overs to spareon Tuesday.Man of the Match all-rounder Steven Smith starred with the ball for Australia, picking up three wickets for 20 runs in his four overs, before David Warner (25) and Brad Haddin(42) guided the team to the target after a few hiccups.Opting to bat after winning the toss, the West Indies were dealt an early blow when Dirk Nannes bowled in-form skipper Chris Gayle (4) off the innings' second delivery.The other opener Shivnarine Chanderpaul (24) departed soon when a miscued shot off Mitchell Johnson's bowling was caught by David Hussey. In his 18-ball cameo, Chanderpaul struck four boundaries. His departure triggered a collapse and the hosts were reduced to five for 60.Ramnaresh Sarwan, the highest scorer for the team with a 31-ball 26, just didn't get enough support at the other end. With wickets tumbling around him, he could not give the acceleration which the West Indies needed desperately.For Australia, Hussey sparkled in the only over he bowled as he picked up two wickets conceding just three runs. Johnson also finished with reasonably good figures of two for 22 in his four overs. With this win, Australia finished the Super Eight campaign on top of their group F ahead of Sri Lanka, who ended runners-up after knocking India out with a five-wicket winon Tuesday.Australia have played Pakistan in the preliminary stage of the tournament and had won that match.