Devon Conway's majestic 92 not out and a superb raft of bowling performances helped New Zealand inflict a shock rout upon Australia with an 89-run win in their T20 World Cup opener in Sydney.

Trent Boult, Mitchell Santner and Tim Southee returned terrific figures in a superb performance to leave the hosts stunned in the first match of the Super 12 stage at the Sydney Cricket Ground.

For the Black Caps, it was a performance to emphatically banish the ghosts of last year's final in the United Arab Emirates, where they buckled against a destructive Baggy Green performance led by Mitchell Marsh.

Here, they clocked a near-perfect start, with opener Finn Allen lashing a destructive 42 off 16 balls before Conway took command following the former's dismissal by Josh Hazlewood through the off-stump.

The wicket-keeper's shrewd knock pushed them to 200-3, setting Australia a difficult target to chase down - and swift dismissals for David Warner, Aaron Finch and Marsh, to reduce them to 34-3, effectively stymied their response.

From there, New Zealand effectively mopped up, working their way through the tail - and when Pat Cummins skied Southee at the start of the 18th over, an easy catch ensured a 111 all out demolition to get their tournament off to a flyer.

Conway throws down marker to rivals

The pyrotechnic performance of Allen came to an end with a choice ball from Hazlewood, the best of the Australia bowlers, but it was Conway's steady presence that built the bedrock.

Left-hander Conway carried the bat through a sumptuous 58-ball innings that included seven fours and two sixes. It is his third half-century in his last five T20I matches - few players are in finer form.

Hosts humbled in poor start

Having downed the Black Caps to crown themselves champions a year ago, this was a performance without bark and bite from Australia.

It is early doors in this competition, but in a group that also contains an England side in rich form, it is a result that could have seismic ramifications for their title defence.