Woeful Australia skittled for 111 - Santner takes 3-31
Conway stars for New Zealand with 92 off 58
Neesham adds late impetus with 26 off 13
Allen's 42 off 16 gets New Zealand off to flying start
England face Afghanistan in day's later game from 12:00 BST
Conway 11, Allen 35
And breathe! 17 from Pat Cummins' first over.
Finn Allen has 35 from just 13 balls! It has been brilliant viewing, taking the Aussies by surprise a little.
T20 cricket can change very quickly but New Zealand are certainly dominating for now.
Matt Clinch
BBC Test Match Special
Short and pulled. Given the maximum treatment by Finn Allen.
I literally cannot keep up.
The ball after the drop went for four over mid-off as Cummins pitches the ball up.
He then tries a short ball and Allen gratefully slots it over square leg for another six! It's brutal!
Chris Green
Middlesex all-rounder on BBC Radio
Image source, Getty ImagesIt didn't look great but I can tell you, that is one of the hardest places to field. You don't get any cues and that came quickly.
NZ 34-0
Oh, it just keeps getting worse for Australia.
It's a good slower ball bouncer from Pat Cummins, Allen doesn't quite get hold of it and pulls it to Adam Zampa at short fine leg.
It's travelling quite fast and Zampa has to jump but he gets two hands on it and the ball just bursts through. Oh, and it goes for four too.
It's all happening!
Chris Green
Middlesex all-rounder on BBC Radio
Gone are the days of having a look early! New Zealand aren't worried about the fresh wicket at the SCG. Allen and Conway are entertaining the crowd and it's great to see.
Matt Clinch
BBC Test Match Special
New Zealand are off to a flyer here at the SCG.
Full, straight but absolutely crunched through the covers for four.
Australia look a bit baffled, New Zealand look in complete control.
Matt Clinch
BBC Test Match Special
Conway joins the party.
Devon Conway skips down the ground and thumps Hazlewood down the ground for yet another four.
This has been a stunning start for New Zealand, especially given they were put in to bat first.
Chris Green
Middlesex all-rounder on BBC Radio
Image source, Getty ImagesThe boundaries keep coming but there is not too much wrong with that delivery from Hazlewood. It was maybe just a fraction too straight.
And the runs keep coming!
Josh Hazlewood, the world's number one ranked T20 bowler, starts with a ball on leg stump that Devon Conway effortlessly nudges down to fine leg for four more.
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Unsurprisingly Mitchell Starc finishes with a short ball that bounces over Allen's shoulder, happy to end the over with a dot ball.
Great start by New Zealand, I don't think the Aussies would have expected that.
Chris Green
Middlesex all-rounder on BBC Radio
Full again from Starc searching for swing but Finn Allen looks very strong down the ground. Pressure on Starc to close out the over.
Drilled back down the ground for four more.
This is class. At just 23 years old, Finn Allen is completely at ease and putting Starc under real pressure.
Chris Green
Middlesex all-rounder on BBC Radio
What a statement Finn Allen is making here in the tournament opener. He holds his shape beautifully and sends the ball into the stand.
Even better this time! Smashed into the stands over mid-wicket!
That is right out of the middle. What a start, Finn Allen!
What have you got, Mitch Starc?
Well. That's a statement of intent if ever I've seen one.
Second ball smashed back down the ground for a one-bounce four!
Lovely.
Chris Green
Middlesex all-rounder on BBC Radio
I'm excited. A rematch of last year's World Cup final. What a clash - and at the SCG. It doesn't get much better.
The Aussies come into this as favourites after starting the last tournament a little bit off the radar.