Boxing Day Test live: Sam Konstas set to debut against India in ...

Labuschagne flashes at a wide one and it looks like a powerful cover drive, but it's actually squirted away pretty square for just a single.

Reddy finds Khawaja's pad and goes up for a ball that pitched a solid foot outside leg stump.

He's "using" his inside edge a lot. Looks like he's getting squared up and trying to work balls to the leg side.

And now he's copped another body blow, this time into the thigh, mercifully.

Four. Siraj bangs in a bouncer and Labuschagne top edges over the keeper. Actually, looks like it was all helmet. Surprised the umpire hasn't piped up. There's supposed to be a concussion check after a batter gets hit on the helmet.

Seven runs off the last three balls for Labuschagne. And he's pinched the strike with a single off the last.

Khawaja brings it up with a boundary through the vacant third-slip region and that's his first 50 since January.

The 38-year-old has been battling in the series and it does appear he was able to build into this innings while Konstas was attracting so much attention.

Whatever the reason, it's good to see him back in the runs.

Four! Lovely stroke from Khawaja — a perfect on drive between the legs of Marnus Labuschagne that beats Washington Sundar to the rope.

Ouch. He's copped the first ball right in the box. Maybe a little higher than the one that cleaned up Konstas.

Oh, but that one was flush. Siraj has absolutely folded him.

It's copybook Liam Livingstone:

Meanwhile, Mohammed Siraj was appealing as Labuschagne folded in half. What a hilarious turn of events.

Another maiden, just with a little more spice.

Labuschagne takes a ball from a long way outside off and clips it to the leg side for a single.

Akash comes around the wicket to left-hander Khawaja and brings a forward square leg into position. That feels very defensive, trying to cut off scoring there. Khawaja likes playing off his pads, but he usually goes more square than that.

Edged ... but again it's straight down off soft hands and falls well in front of Virat Kohli at second slip.

Khawaja plays a lovely straight drive but Akash cleans up off his own bowling.

Edged ... but safely into the ground about a metre or two in front of Virat Kohli at second slip.

And then the next ball jumps up at Labuschagne, hitting the bat in the stickers.

An incredibly tight leave from Labuschagne to a ball nipping back in at him and just clearing the top of the stumps.

Bumrah tries the bouncer, but Marnus gets under it relatively easily.

Labuschagne takes his first run of the session off his 18th delivery, clipping a single off his pads.

Bumrah overstepped though, so he'll have to bowl one more ball to Khawaja from around the wicket.

Bang! Short and crushed over mid-wicket for four. That ball wasn't particularly short, but Khawaja picked it up earlier and pulled his favourite pull shot.

Beaten! What a response from Akash, angling in and seaming away to beat the outside edge.

And again. Khawaja tries a couple drives and misses out. I wonder if he'll put the scoring shot away again now.

Another one past the edge. This time getting him on the hop.

We're still yet to see a run scored in this session.

Labuschagne is defending against a ball that stays low on the stumps. We've seen a couple jump up and a few skid on. This pitch might become a little easier on days two and three.

Labuschagne curses himself for failing to cash in on a ball on his pads.

Four straight maidens to start the second session.

Khawaja is digging in here, and immediately looks similar to what he has for the rest of the series. Stuck on the crease and at risk of nicking off.

While Konstas was flailing away, it felt like the senior batter could just fly under the radar, but now the pressure is back on.

Another maiden.

I agree, but I wouldn't say it was exactly out of character for Virat. Maybe just the same stuff dialled up from an eight to an 11.

Marnus Labuschagne in his sight, and he's leaving outside off to start.

Labuschagne is defending.

Bumrah spears it down leg and Rishabh Pant covers good ground to rein it in. There's some interest from the bowler, but the ball was nowhere near the bat.

What will this session deliver after the explosive opener?

And straight away Akash is beating the outside edge of Khawaja from around the wicket. Khawaja has struggled with that line. He is still stuck on the crease.

Khawaja plays his first attacking shot of the session but doesn't quite time it and it's straight to mid-off.

A maiden to start. We're back to regularly scheduled programming with Sam Konstas back in the sheds.

The first session in the fourth Test is in the books, and it was well and truly Australia's.

The story of the session is none other than Sam Konstas.

There was significant hype around the 19-year-old's debut, and I think he exceeded it with an absolutely audacious, yet brilliant innings.

Jadeja removed him with a vital wicket for India in the final half hour of the session, but the tourists need a few more.

Konstas took the attack to Bumrah, who has had Australia's number all summer, and it definitely rattled India, there is no question.

His aggressive approach also seemed to free up Khawaja, who has looked the most fluent he has all summer.

Time for us all to get a breather before we return.

Australia well on top, but a few quick wickets could get India right back into this.

Khawaja lives dangerously again! He's squared up from one around the wicket from Bumrah, but luckily for him, it flies through the gap towards third man for a couple.

Another one that makes Khawaja look awkward! Bumrah gets the ball to rise up off a length and it's defended, as Khawaja takes one hand off the bat as a precaution.

It's almost a Steve Smith dismissal for Marnus to end the over and the session, as he misses an attempted flick.

Akash Deep has simply switched ends, replacing Ravindra Jadeja.

Three slips and a gully in as Deep starts to Marnus.

A bit too straight with the first delivery, as Marnus works it off his pads for a couple of runs through midwicket.

Another one on Marnus's legs, this time it's just a single as Siraj goes to throw down the stumps from mid-on, but fumbles the ball.

Another good ball from Deep to Khawaja, which rises up and strikes him in the midriff. Khawaja's been out there the whole time, but he's not really looking super comfortable of late.

Just as I type that, Deep goes full and is driven through the off side by Khawaja for three. A diving stop from Siraj at mid-off prevents a boundary.

Here we go.

Rohit Sharma goes back to his strike weapon, who was uncharacteristically dismantled in the morning by Konstas.

34 of the 38 runs Bumrah conceded in his first six overs were off the bat of Konstas, a lot of them over the slips cordon with that ramp shot.

A good move with Marnus fresh at the crease.

Bumrah immediately makes life difficult, and gets one to leap up off the back of a length to strike Khawaja.

There is also a somewhat muted LBW appeal, but Khawaja managed to get some bat on the ball there.

Meanwhile, a Mexican Wave has erupted around the MCG as Sam Konstas signs some autographs.

A nice lap sweep from Khawaja as he gets a couple while the ball trickles down to fine leg.

Jadeja again strays onto Khawaja's legs and he's flicked away for a single. He's struggled to get his line right to the left-hander so far.

FOUR! Marnus is off and running! Not a bad delivery from Jadeja, but Marnus unleashes a lovely late cut. Deft touch.

FOUR MORE! Same ball, same result! Marnus glides this one past KL Rahul at backward point, who hangs his head.

Brings up the 100 for Australia, what a terrific morning this has been for the home side after Pat Cummins won the toss.

BEATEN! Excellent this from Deep. Another one which pitches and leaves Khawaja ever so slightly from around the stumps, and beats a prod from the left-hander.

Khawaja gets one on his legs and works through to the leg side for a single to fine leg.

Deep tidy again for the final two deliveries to Marnus.

His five overs have gone for just nine runs, which has allowed India to wrestle back some of the momentum after the Konstas madness from earlier.