Smith 229*, M Marsh 181*
Fifth-wicket stand worth 301
Marsh's maiden Test century
England take only one wicket in day
Australia lead 2-0 in five-match series
Play starts at 02:30 GMT on Sunday
Smith 216, M Marsh 171
This partnership is up to 273. Not many England innings in Australia reach that sort of mark.
Dawid Malan is genuinely bowler of the day I think, he chucks in a wrong 'un to the delight of the TMS box.
But then Steve Smith laces a cover drive to the fence.
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Waca'd.
Dom, Kilburn
750! Ha ha ha.
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Think Aus will bat for another 2-3 hrs tomorrow. Amass something approaching 750. Send us in thoroughly dejected. Skittled for 150. Fingers crossed I'm wrong. We fly out Weds...
Rob H
Ed Smith
Ex-England batsman on BBC Test Match Special
That's dismissive from Marsh.
Smith 211, M Marsh 171
Shot! Mitch Marsh steps onto a short ball from Stuart Broad and sends his figures past the 0-100 mark.
And another! Four more to Marsh, now batting like Gilchrist, Botham or Flintoff. He wasn't even the best batsman in his house this morning. Now he's carting England from pillar to post.
He could well overtake Steve Smith soon...
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Annoying.
Josh, Abu Dhabi
Smashing.
James, Glasgow
Can it get any worse? Yes. Stuart Broad looks like he's sunburnt now. He's really caught the sun.
It's the only catch all day. Wahey!
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Ashesless.
Ian, Cheshire
Image source, ReutersSmith 211, M Marsh 161
Steve Smith blocks away another Dawid Malan over. Smith is making sure he's there for tomorrow I reckon. He could do with a bit of time in the middle.
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Sublime.
Stuart, Winchester
Lead by 108
If anything sums up England's day it's the sight of their most successful bowler of all time jogging in for his 29th wicketless, chanceless and hopeless over of the innings.
He had one lbw shout turned away for a no-ball. That's it. Not even a dropped catch. Jimmy Anderson would pay good money for a shelled catch right now.
28.5 of those overs have been full, at middle stump. That's just my estimate, not an official stat.
Dawid Malan! That's very nearly a beauty, bit of drift in to Mitch Marsh and it nearly wraps him up. That goes down as probably ball of the day.
A horror show of a day for England.
Moeen Ali removed Shaun Marsh for 28 early today, but that is England's only success in two and a half sessions.
Steve Smith, inevitably, has proved the biggest of stumbling blocks, converting his overnight 92 into a sensational, chanceless double century. And he's still there.
Mitchell Marsh - recalled for this match - has been even more destructive, battering his way to a maiden Test century and beyond.
Australia have just reached 500 and the fifth-wicket partnership has passed 250. This is getting ugly for England, who must avoid defeat if they are to have any chance of retaining the Ashes.
Image source, EPA
Simon Mann
BBC Test Match Special commentator
We've had the Marshes batting from one end all day, and Steve Smith batting from the other.
Smith 209, M Marsh 161
The lead is over 100 now for Australia. What sort of lead will they get before they declare? Two whole days left of course.
As Glenn McGrath mentions some cakes they've been sent out in Perth, a gentle reminder that we are very much open to any baked goods you'd like to send in.
You can get them to us at
Quay House
Salford Quays
Salford M50 2QH
Glenn McGrath
Ex-Australia pace bowler on BBC Test Match Special
They don't look like they're vicious turners, but Malan has landed them in the right area.
Smith 208, M Marsh 156
Dawid Malan has a career best of 5-61 in first-class cricket. The collapse could be on yet!
I wonder why Joe Root has asked for him to bowl now though? He could have done this at any point in the last six hours.
'When Smith calls for a chair, that's the signal mate. You're on.'
Simon Mann
BBC Test Match Special commentator
Good luck, Dawid...