James Anderson is fielding right in front of Steve Smith at the non striker's end, which means the two of them can have a nice chat. Smith leans on his bat and ignores him.

A single brings the Australia captain on strike, and Overton finds the outside edge of the bat! That's good from Overton, just tempting Smith to come forward and have a nibble, but it goes on the bounce to Alastair Cook at slip. "That's the most Cook's had to do in three days," Tom Rostance sniffs from next to me.

Ideas, anyone? Joe Root would love to hear them.

He's turned to Craig Overton, undoubtedly England's best bowler in this Test, to try and break this pairing up.

Four for Steve Smith, despite Craig Overton's best efforts as he chases after the ball and ends up sliding into the boundary rope. You could hear a pin drop out in the middle. There's no noise from the England fielders.

The only sound comes from Smith, the ball thudding into the bat as he carves away the single to bring up the 100 partnership from 133 balls. It feels like it's come around in no time at all.

50 for Marshpublished at 96.1 overs

96.1 overs

Aus 343-4

And that'll be 50 for Mitch Marsh.

He has a huge grin as he raises his bat to his hometown crowd. He's not looked particularly fluent at times but he can't half strike a ball. It's taken him 75 balls to get to his half-century, with seven fours.

Moeen, the day's only wicket taker, is coming on for a bowl to Mitch Marsh.

Warren Craig, Steve Smith's manager, on TMS: "If he’s at home and he can’t find anyone else to go and practise with, he gets his fiancée to feed balls into the bowling machine just so he can go and have a hit.

"Dani enjoys that part of things. She has been absolutely fantastic for Steve. They’ve been together for about six years.

"She is such a pivotal part to the success of what you see on the field. She’s a calming influence. She knows when his mind is ticking over too much, to sort of get his mind away from cricket. They are a great couple of and got engaged recently."

Image source, Gett

Shot! Mitch Marsh frees his arms and slaps a wide Chris Woakes delivery over the heads fo the fielders and away for four. A single takes him to 49. He's made two Test half-centuries before, but he's yet to turn it into three figures. Smith then rolls his wrists and pirouettes, pulling for two, before he leaves extravagantly.

Yes, Will. Yes.

Here's Smith's wagon wheel, and he's scored all around the ground. And it's not all been boundaries either. So many ones and twos mixed in there. If England had any oomph this morning, Smith has taken it right out of them.

Image source, Opta

A frustrated Mitch Marsh swishes at a Stuart Broad short ball and just about avoids gloving through to Bairstow. A bit of extra bounce might have surprised Marsh there. He had to yank his head out of the way as he went through the shot.

Steve Smith, on the other hand, is having no trouble with the short ball. A back foot punch races off the bat and the ball goes tearing down to the boundary.

Michael Vaughan
Ex-England captain on BBC Test Match Special

Image source, EPA

Once Ben Stokes wasn't coming to Australia England had to replace his bowling. His batting is brilliant but don't forget his impact as the fourth seamer.

He goes for a few runs an over but he makes things happen. Liam Plunkett would have done that for England, he should have been in a four-man attack.

England have to look at what has happened here. They have to be honest and have a four-year plan to be competitive in Australia, with this ball and in these conditions.

They have been whitewashed in 2006, whitewashed in 2013 and are struggling again. For England's development we need to look at the pitches we prepare back home.

This is the seventh time Smith has reached 150 in Tests. To be honest, it's felt almost ienvitable since he wandered to the crease yesterday.

Chris Woakes spears a ball wide, trying to tempt Smith into a loose drive, and the Australia captain turns his back on it and ignores it.

150 for Smithpublished at 93.3 overs

93.3 overs

Aus 330-4

A wave of the bat, a nod of the head and a handshake for Steve Smith as he drives through the covers to reach his 150.

He doesn't look even remotely tired. Utter concentration.

'Not ideal...'

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Simon Hughes
BBC Test Match Special commentator

Smith did make that double hundred at Lord's, but it was a flat pitch. But English conditions are unique - the swing of the ball. That's the one place that Smith hasn't yet conquered.

Steve Smith, on 149, nods his head at Stuart Broad as he ducks underneath a well-directed bouncer. Broad then squares him up and stops him working a single away.

Mitch Marsh hasn't started things quite as fluently as his captain. Stuart Broad cramps him from room and Marsh, half ducking, half playing, dribbles an edge down to the floor. This is good from Broad, following it up with a short ball that whizzes across Marsh's shoulder on its way through to the keeper.

Marsh will sneak three, though, as Broad goes tearing across the wicket to field a little push and ends up knocking it down the pitch.

Stephan Shemilt
BBC Sport in Perth

Image source, BBC Sport

This is the oval of Trinity College, the school that is across the road from the Waca. A decent hit from here would clonk the concrete of one of the floodlights. To the left is the pavilion named after a former student that went on to open the batting for Australia, Simon Katich.

Ooh! Steve Smith pulls a disgusted expression as an off-cutter from Chris Woakes rears up at him, and Smith flaps his hands down at it. I wonder if that hit one of the cracks that are creeping up the Waca pitch.

He still absolutely nails a pull shot for four, though. A step back, a roll of the wrists, and a short ball from Woakes flies to the boundary.

Michael Vaughan
Ex-England captain on BBC Test Match Special

If England lose the next 30 or 40 minutes, the whole series could be gone.