Stoinis hits sublime 17-ball fifty to guide hosts to seven-wicket win
Both sides have now won one, lost one
Aus 158-3 (16.3 overs): Stoinis 59* (18); Dhananjaya 1-18
SL 157-6 (20 overs): Nissanka 40 (45), Asalanka 38* (25); Maxwell 1-5
Clint Wheeldon
BBC Test Match Special
I think Pathum and Dhananjaya are in a really good place here for a partnership. If they can get into the 10 overs, then they have a really good platform for the next 10 overs.
There's a change at the other end too as Marcus Stoinis trundles in, mixing up his pace and length.
Dhananjaya de Silva is a touch unlucky not to have a couple of boundaries as a cross-batted swipe smashes into the stumps at the other end, before a pull shot goes straight to mid-wicket.
Textbook.
Dhananjaya de Silva skips down the track and smashes new bowler Ashton Agar through mid-off and away for a four.
Sri Lanka are starting to get going after that slow start.
Australia made a great start to this match, removing the dangerous Kusal Mendis for just five.
Clint Wheeldon
BBC Test Match Special
Sailed over Wade and another four. The extra pace in the surface here means Australia are employing a short ball tactic.
We knew this Perth pitch had some extra bounce and that is a prime example. Josh Hazlewood bangs it in and the ball takes off, flying over both Dhananjaya de Silva and Matthew Wade towards the rope for four byes.
Sri Lanka scramble their way to 36-1 at the end of the powerplay.
Clint Wheeldon
BBC Test Match Special
Bounces twice and into the ropes for four and again we see the pace.
We saw Cummins take a wicket off a ball not too dissimilar to that, so Sri Lanka are living dangerously.
Josh Hazlewood continues for his third over to complete the power play.
Pathum Nissanka has been swinging hard without much success so far - but finally makes contact and the ball top-edges right over wicketkeeper Matthew Wade and away for four.
There's not much swing for Mitchell Starc but the change of angle bamboozles the Sri Lanka batters, with Pathum Nissanka going for three huge swings and misses.
A single and two leg-byes completes another fine over in the powerplay for Australia. Sri Lanka have hit just three boundaries so far.
Jason Behrendorff
Former Australia bowler on BBC Test Match Special
The energy is up tonight and if Australia don't win well then the World Cup is potentially over for them.
Australia are sharp in the field so far, with Glenn Maxwell and Ashton Agar making diving stops in the point region.
They cannot do anything about that, though. Dhananjaya de Silva plays a beautiful late cut shot that's perfectly placed just wide of Agar and flies away for four.
Time for a change of bowling. Here's Mitchell Starc.
Josh Hazelwood strays off line with back-to-back wides. Matthew Wade tried to claim a nick off the bat on the way through with the second wide, but umpire Marais Erasmus was having none of it.
That was a good over for Sri Lanka in the end - 10 off it.
Shot.
Pathum Nissanka gives himself some room and Josh Hazlewood follows him, but the Sri Lanka batter reacts quickly and clips the ball through square leg for four.
Nissanka mistimes the next shot but his drive has enough power on it to fly over David Warner at mid-off and Sri Lanka can run two.
Ben Cameron
BBC Test Match Special
Australia are on top early. Mitchell Marsh has taken a conventional catch and the ball is in safe hands.
Jason Behrendorff
Former Australia bowler on BBC Test Match Special
That is not actually not that short a delivery. He tried to play the pull when it probably wasn't on but the extra bounce here in Perth has worked in Australia's favour.
Mendis c Marsh b Cummins 5 (SL 6-1)
Big wicket for Australia!
It's short from Pat Cummins but Kusal Mendis' attempted pull from off to on top-edges into the sky and Mitchell Marsh takes the catch running in from midwicket.
Flash, flash hard. A whip of the blade by Kusal Mendis flashes off the edge and flies over where second slip would be and away past third man for four.
Not the most convincing of shots by Mendis, but they all count.
Good start by Josh Hazlewood as he extracts a bit of movement off the pitch away from the Sri Lanka openers. Twice he beats the outside edge of Pathum Nissanka's bat, with just the two singles conceded.
Pat Cummins will open at the other end ahead of Mitchell Starc.
There are plenty of Sri Lanka flags being waved in the crowd during their national anthem, before 'Advance Australia Fair' is belted out with gusto by the majority of the spectators. Around 25,000 fans are expected which should make for a decent atmosphere.
Pathum Nissanka and Kusal Mendis - the top scorer in the tournament so far - will open for Sri Lanka.
Josh Hazlewood, the number one T20 bowler in the world, will open the bowling for Australia.
Let's go...
Sri Lanka: Pathum Nissanka, Kusal Mendis (wk), Dhananjaya de Silva, Charith Asalanka, Bhanuka Rajapaksa, Dasun Shanaka (c), Wanindu Hasaranga, Chamika Karunaratne, Maheesh Theekshana, Binura Fernando, Lahiru Kumara.
Australia: David Warner, Aaron Finch (c), Mitchell Marsh, Glenn Maxwell, Marcus Stoinis, Tim David, Matthew Wade (wk), Pat Cummins, Mitchell Starc, Ashton Agar, Josh Hazlewood.