Shane Watson scored a half-century after being dropped on four to guide Australia to an emphatic six-wicket victory over Pakistan in Adelaide and send the co-hosts into a World Cup semi-final with reigning champions India.

Fired by a four-wicket haul from recalled paceman and man-of-the-match Josh Hazlewood, Australia bowled out Pakistan for a modest 213 and after surviving a wobble in the chase, all-rounder Watson (64 not out) and Glenn Maxwell (44 not out) reeled in the total with more than 16 overs to spare.

Steven Smith was also instrumental, scoring a classy 65 to steer Australia as Watson weathered a furious short-pitched attack from fast bowler Wahab Riaz.

Pakistan's bowlers had little to defend at Adelaide Oval and were let down badly by two spilled catches that could have changed the complexion of the match.

Australia were vulnerable at 83-3 under a fiery spell from Wahab, but Watson was dropped on four hooking straight to Rahat Ali at fine leg, the simplest of chances bouncing straight out of his hands.

Maxwell later sent a top edge soaring but Sohail Khan put down another gettable chance on the run to leave Wahab grimacing in frustration.

Hazlewood, who replaced young seamer Pat Cummins, combined with left-armer Mitchell Starc to remove Pakistan's openers cheaply and returned to punch a hole through the Asian team's middle-order on a sun-drenched autumn day.

Part-time spinner Maxwell took two wickets while Aaron Finch took three catches at deep midwicket, as Misbah and two other Pakistan right-handers gave up their wickets on a platter when attempting to clear the short boundary.

Pakistan's tailenders nudged their team past 200 and though Wahab (2-54) battled hard to shake up Australia, Pakistan will ultimately be left wondering what if.

Scorecard:

Pakistan 213 all out in 49.5 overs (Sohail 41, HAzlewood 4-35)

Australia 216-4 in 33.5 overs (Smith 65, Riaz 2-54)