Smith hit 116 for Australia in his side's 297-9
England bowled out for 285 - Vince top scores with 64
Smith & Warner were playing against England for first time since ball-tampering bans
Warner hit 43 before holing out in the deep
Both Smith & Warner booed when they walked out to bat & at milestones
Liam Plunkett was England's most successful bowler. He dismissed Warner and also claimed the wickets of Shaun Marsh, Alex Carey and Nathan Coulter-Nile.
Check out the fine catch from Tom Curran to dismiss Carey below...
Both Smith and David Warner were booed by members of the crowd in Southampton as they play against England for the first time since the ball-tampering scandal.
Warner opened the batting and scored 43 from 55 balls.
He wasn't at his big-hitting best but hit five fours.
Smith was eventually out for 116 from 102 balls in controversial fashion.
It looked like he had hit this into the ground but he was given out by the third umpire.
Smith's innings was the mainstay of that innings. No one else passed 50.
He didn't bat particularly aggressively and there were long spells without a boundary in the Aussie innings.
Eventually Smith got to his 100 from 94 deliveries, shortly after hitting a his first six.
It is his first hundred for Australia since returning from his ban following the ball-tampering scandal.
Thanks Tom.
On paper this looks like a total England will be comfortable of chasing.
They scored 373 on this ground a couple of weeks ago against Pakistan. They followed that with successful chases of 359 and 341.
So another century for Steve Smith against England. I don't think that will be the last time I write that this summer.
Time for me to take a break, here's Matthew Henry to take the wheel.
'I'm just happy to be back playing'
Australia batsman Steve Smith: "It was nice to score some runs out there and spend some time in the middle. I’m looking forward to fielding later on and get some miles in the legs.
On the Boos: "I’m pretty chilled about it. Everyone is entitled to their opinion and I’m just happy to be back playing. Fortunately, I was able to contribute today and hopefully I can take this form into the World Cup.
Is 297 enough?: "England are a very good side and they chase over 300 regularly so we have to play very well. It would be nice to win, we are still working on our skills ahead of the first game but winning is a habit. The boys have been on a good run and hopefully we can take that into the tournament.
So England require 298 to win. A competitive total but not beyond this England side's capabilities.
Zampa run out (Buttler) 1 (Aus 297-9)
Another run-out. With little to lose Adam Zampa goes for a second on the final ball and ends up a long way short.
England keep Australia below 300.
Jack Skelton
BBC Sport in Southampton
About two seconds of cheers for the wicket before the pantomime boos begin. Steve Smith could have done without that - a few wags were barracking him for not walking before the third umpire decision came back, not that he'd have really been able to tell that wasn't a bump ball. It was so tight.
Adam Zampa will face the final ball...
Charles Dagnall
TMS commentator
This is going to happen to Steve Smith all summer, he won't be able to escape the boos.
Charles Dagnall
TMS commentator
What?! I can't believe that. Because the soft signal was out, he thought there wasn't enough evidence to overturn it.
Smith c & b Curran 116 (Aus 296-8)
That was unexpected. It looked like a bump-ball initially but the third umpire did not see enough evidence on the replay to overturn to soft signal. Smith is on his way once again to a smattering of boos but also plenty of applause.
Charles Dagnall
TMS commentator
I think he's going to be not out here.
The umpires are looking at a possible caught and bowled chance for Tom Curran....
Charles Dagnall
TMS commentator
That got what it deserved.
Bang! Big six from Steve Smith! He hits a slower ball from Tom Curran back over mid-off.
The next delivery from Tom Curran is forced into the onside but an England fielder is quickly on it to save the run.
Tom Curran to bowl the final over...
Steve Smith slices the first delivery but it lands safely and he gets two.