Smith 92*, S Marsh 7*
England drop three catches
Two wickets for injured Overton
Khawaja 50, Bancroft 25, Warner 22
England slip from 368-4 to 403 all out
Malan 140, Bairstow 119; Starc 4-91
Australia lead 2-0 in five-Test series
Michael Vaughan
Ex-England captain on BBC Test Match Special
The problem is if there's a muscle tear.
England will have the technology to scan it in the dressing room. Craig Overton is a tough chap, he won't be strolling off there isn't a problem.
Craig Overton has indeed left the field. It's a slow walk off for the Somerset man. Fingers crossed that it's nothing too serious.
Image source, Getty ImagesSteve Smith offers no sympathy for Overton, as he meets a tasty short delivery with a dismissive slap. That's four, and Overton grimaces in both discomfort and annoyance. He's not right.
Smith goes for a big swing and the ball flies tantalisingly close to Moeen in the deep, but it bounces in front of him. Overton trudges back to his mark, looking utterly disconsolate.
Glenn McGrath
Ex-Australia pace bowler on BBC Test Match Special
That left hand side of the abdomen is where you get your power from if you are a right-handed bowler. They call it the grunt muscle. That's causing Overton a problem.
There's a consult between captain Root, the England fast bowlers and Overton, and Overton waves them away. He's going to continue.
There's a lot of head shaking going on as Overton gets his side moved up and down by the physio. Geoffrey Boycott reckons its a strain in his left side.
Short, wide, down the leg side from Overton and Usman Khawaja gets a healthy bit of bat on it to help it away for four.
Oh, Overton's struggling. He grimaces in his follow through, a few seconds after hes' released the ball, and bends over, holding his side. He's holding his rib - I think very close to where he was struck when batting in Adelaide. Out comes the physio.
Image source, Getty Images#bbccricket
Image source, Twitter
Andrew Samson
BBC Test Match Special statistician
This is Smith and Khawaja's fifth hundred partnership. They have scored 1,094 runs together in Tests.
Image source, Getty ImagesTrail by 244
James Anderson's looking disgruntled out there. The ball's doing nothing and Usman Khawaja has found a bit of rhythm now. A drive down the ground brings up he 100 partnership between this pair, and they meet in the middle to punch gloves.
Too wide now from Anderson, and Smith leans back and crashes it to the boundary. Even he was impressed by that, if the look of pride on his face is anything to go by.
Just waking up? Bit late, isn't it? Christmas party last night?
It has been Australia's day so far, and it will remain that way while Steve Smith is still at the crease.
The Australia captain is unbeaten on 61, while Usman Khawaja - dropped on nought and 28 - has 43, with the hosts 154-2 in reply to England's 403.
That total was something of a disappointment given that there were 368-4. But Dawid Malan's dismissal for 140 was the first of fix wickets to fall for 35 runs in nine chaotic overs. Jonny Bairstow, for the record, made 119.
England need a wicket.
Image source, Getty ImagesFull and straight to Usman Khawaja first up, and Khawaja bunts it rather awkwardly back down to the bowler. Overton, knees pumping up to his chest, steams in and Khawaja pulls, but it's down along the ground and a superb dive by James Vince stops the ball reaching the boundary. A real hand stinger for Vince, leaping to his left and sticking a mitt out to take the pace off the ball.
Shot! Four! Oh, Smith pulls so well, and the ball absolutely flies across the Waca outfield and into the boundary rope as he swivels.
Aha! Here's Craig Overton, who has taken both of the Aussie wickets to fall so far.
Stephan Shemilt
BBC Sport in Perth
Image source, BBC SportI kid you not. A commentator on Aussie TV has just said that it's "a touch overcast".
Glenn McGrath
Ex-Australia pace bowler on BBC Test Match Special
Pick up one wicket and things can change very quickly. England need to be thinking that, one wicket here can turn things around.
Never just think "we're out of it... its over." You're always in the game.
Incidentally, if you have any ideas on how to dismiss Steve Smith, there's a Mr J Root in Perth who would be very interested in hearing your views. I'd give Craig Overton a bowl. It's the only time Smith looked vaguely uncomfortable. James Anderson decides to go straight at Smith, and he meets everything with the middle of the bat. Maiden.
It's time for drinks and, presumably, a pep talk for England from the captain.
Text 81111
Image source, Reuters'I din't see it mate,,,'
Red lenses don't make things red, they remove non-red light from what is coming to your eye, thus making red things more prominent. If something isn't red, you cannot make it red by looking at it! The light comes to you.
Tim, London
Trail by 254
Usman Khawaja is in on the act now as he turns his wrists on a straight ball from Chris Woakes and whips it away for four. That's a lovely touch. Woakes readjusts and drags Khawaja back into his shell as he returns to defending.
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Glenn McGrath
Ex-Australia pace bowler on BBC Test Match Special
Things are looking OK for Australia. There's still a long way to go - you only have to pick up one or two quick wickets. They're very poised.