Opener Shane Watson and a slew of middle-order cameos collectively upstaged all-rounder Kieron Pollard's century, as Australia trumped the West Indies by five wickets in Friday's fourth ODI at the Sydney Cricket Ground.

Pollard's unbeaten 109 weighed in as the third ton of his career, and second against the Australians, ultimately pushing the Windies to 220 all out in 49.2 overs.

The tally wasn't nearly enough, though, as the Aussies bettered their unassailable series lead with all of 31 balls to spare, leaving Sunday's fifth and final ODI in Melbourne ripe for a whitewash.

Watson's comfort at the top of the knock was again prevalent. The all-rounder, who has opted not to bowl for the foreseeable future in order to remain injury free, continued to prove his worth as a batsman alone.

Friday's 76 wasn't as fluid as Wednesday's 122, requiring a couple of lifelines for its number, but certainly cemented his position amid consistent questions as to the validity of his selection.

Watson's stay would've ended on 32, and again at 51, had wicketkeeper Devon Thomas not grassed a straightforward chance to his right and fielder Narsingh Deonarine not failed to orchestrate an easy run-out opportunity at the non-striker's end.

Opener Aaron Finch, the left-handed Phil Hughes, captain Micheal Clarke and the recalled Adam Voges, meanwhile, garnered 25, 23, 37 and 28 respectively. There was little challenging about their stints at the crease, aided by a largely empty West Indian attack.

Finch and Hughes, in particular, only had themselves to blame for premature dismissals. Voges, at least, offered the selectors food for thought after replacing the injured George Bailey.

The Windies, too, were minus a first-choice batsman. Opener Chris Gayle missed the match due to a side strain sustained during the third ODI in Canberra. His presence, largely short of form this year, ultimately was not missed. Pollard, instead, bridged the gap, though his effort was a vain one.

The talented right-hander's tempered 136-ball stay contrasted an approach often laden with brazen flair, and shepherded the lower order with superb responsibility. Pollard enjoyed 35-, 64- and 23-run stands with tail-enders Andre Russell, Sunil Narine and Tino Best respectively.

Seamer Mitchell Johnson was the pick of the home bowlers, snaring three wickets in a telling opening spell, and was well complemented by all-rounder Ben Cutting's figures of three for 45.

A five-match affair that initially promised tight competition has been rendered largely one-sided by the Windies' inadequacies - and Australia's professionalism in front of appreciative home crowds. Sunday in Melbourne is expected to bring the same.