Get Involvedpublished at 04:18 Greenwich Mean Time 7 January 2018
#bbccricket
Malcolm McLeod: For the next Ashes series England should insist that they get to bat on the same wickets as Australia as this one appears completely different now!
Root 42*, Bairstow 17*
Two wickets for Lyon
Aus 649-7 dec - lead of 303
S Marsh 156, M Marsh 101
Moeen 2-170, Crane 1-193
Australia lead five-Test series 3-0
Day five starts at 23:30 GMT
Jack Skelton and Amy Lofthouse
#bbccricket
Malcolm McLeod: For the next Ashes series England should insist that they get to bat on the same wickets as Australia as this one appears completely different now!
Vic Marks
Ex-England spinner on BBC Test Match Special
I don't see this tour as a calamitous one - not the way it was four or 12 years ago, when everything fell apart.
And England's reply? Well, it's not been pretty.
Mitchell Starc had both openers playing and missing from the off, before he snared Mark Stoneman lbw, which England unsuccessfully reviewed.
Nathan Lyon then came on and cast the efforts of England's spinners into sharp relief with some even sharper turn - bowling Alastair Cook for just 10 with a peach of a delivery.
James Vince and Joe Root have steadied things very slightly since but England face an almighty battle to save this Test and avoid a 4-0 series defeat.
So a wicket that has looked utterly flat for two days might actually be a pretty good cricket pitch. Who knew?
Not England. They toiled gamely but unsuccessfully for the first half of a scorching day four, with first Shaun Marsh then brother Mitchell both completing their centuries.
Mitchell was bowled by Tom Curran a ball after reaching the landmark, while Shaun was eventually run out for 156.
More runs from Tim Paine, Mitchell Starc and Pat Cummins compounded England's misery as Australia declared on 649-7 - a lead of 303.
Trail by 278
Vince taps one off the first, leaving Root a maximum of five balls to negotiate.
Lyon tries one more round the wicket - nothing doing, so he goes over the wicket instead.
He tries to slide the first into Root's pads but the skipper fends it away. Root then calmly plays out the rest of the over.
That's tea. Phew.
One over until the tea interval. Lyon to bowl it.
Can Vince and Root survive?
Vince 5, Root 8
The first really banged in short ball of the innings from Hazlewood has Vince failing to weave out of the way as it cracks into his upper arm.
He's unruffled though and drops the next one into the covers for a quick single.
Text 81111
Too hot for the cricket so we’ve headed to Coogee beach, looks like it was the best decision!
Henry
Trail by 280
Nathan Lyon still round the wicket to Joe Root, who rocks back or forward to defend all six. A maiden.
Stephan Shemilt
BBC Sport in Sydney
The chap in the white T-shirt has been spraying the crowd with water from what looks like a piece of gardening equipment. He's now on his way to spray whiskey in the England dressing room.
Vince 4, Root 8
Nathan Lyon finishes signing hats and bats just about in time to sprint around from fine leg to stop a Joe Root flick going to the fence. More applause - 'Garry' is currently king of the SCG.
Josh Hazlewood - back into the attack - is met with a few solid James Vince defensive strokes.
#bbccricket
Out of ideas: Can we just forfeit and get this over with?
Dan Norcross
BBC Test Match Special
England are in all sorts of terrible and diabolical trouble.
Trail by 283
James Vince calmly plays out a maiden from Nathan Lyon, using his feet nicely to smother the spin off the last.
That Lyon ball to dismiss Cook turned 5.3 degrees. Vicious.
Vic Marks
Ex-England spinner on BBC Test Match Special
And that's with one score of over 50!
Andrew Samson
BBC Test Match Special statistician
Alastair Cook finishes the series with 376 runs at 47. It's the eighth time Nathan Lyon has dismissed him - his average against Nathan Lyon is now 25.12
Vince 4, Root 5
Root works Starc off his pads and round the corner for two. And then does the same again.
Dan Norcross
BBC Test Match Special
This has a feel of desperate difficulty and carnage.
Amy Lofthouse has just pointed out that there are now a few clouds over the SCG, casting large parts of the field in shadow, after England fielded all day in scorching sunshine.
"Even the weather hates England."