Day five of the Australian Open
Use audio icon to listen to BBC Radio 5 Sports Extra commentary (UK only) of Jasmine Paolini v Renata Zarazua
Defending champion Jannik Sinner beats world number 173 Tristan Schoolkate 4-6 6-4 6-1 6-3
GB's Katie Boulter loses 7-6 (7-3) 2-6 6-2 to Veronika Kudermetova in second round
Emma Raducanu wins 6-3 7-5 against Amanda Anisimova to reach third round for first time
*Kudermetova 7-6 (7-3) 2-4 Boulter
Katie Boulter does not know when she is beaten.
It looked like it was going to be a straightforward hold for Veronika Kudermetova to consolidate that break.
But from 40-0, Boulter has a break point.
*Sinner 4-6 0-1 Schoolkate
How will Jannik Sinner respond now? The defending champion has challenged Tristan Schoolgate in his service games, but the Australian somehow manages to find a way through each time.
He does the same again here, firing down two aces en route to the hold.
Sinner 4-6 0-0 Schoolkate*
Abigail Johnson
Commentator on BBC Radio 5 Sports Extra and BBC Sounds
The crowd are getting loud because they are getting conducted by Tristan Schoolkate, the 23-year-old Aussie who is making is main draw debut.
It's Schoolkate who is embracing the atmosphere and really teeing off in that final game to great effect.
*Kudermetova 7-6 (7-3) 2-4 Boulter
Oh hello.
The shoe was on the other foot in the first set with Veronika Kudermetova a double break up but Katie Boulter finds herself in a bit of bother after some brilliant returning from the Russian.
She immediately overturns the break and we're back to just the single one.
Sinner 4-6 0-0 Schoolkate*
Wow! I don't think many of us were expecting that.
Jannik Sinner goes for power with the forehand, but he finds the fence and hands Tristan Schoolkate the opening set.
A reminder that Schoolkate is ranked 172 places lower than the defending champion. This would be a massive upset.
Image source, Getty Images*Kudermetova 7-6 (7-3) 1-4 Boulter
Got it!
Veronika Kudermetova fires long and that's the double break for Katie Boulter.
She fist pumps and lets out a roar as she heads to her chair.
Kudermetova 7-6 (7-3) 1-3 Boulter*
Katie Boulter not messing around here. She wants another break to put this set to bed.
She works herself three break points.
*Sinner 4-5 Schoolkate
Now then, what can Tristan Schoolkate do here? He's got himself a three set points against world number one Jannik Sinner!
Kudermetova 7-6 (7-3) 1-3 Boulter*
Another service game under the belt for Katie Boulter, still with that break in tow.
She'll want to get this set in the bag to ensure herself a decider.
*Sinner 4-5 Schoolkate
It's more like a table-tennis match at times on Rod Laver Arena, with Tristan Schoolkate winning a rapid-fire play at the net and getting a big cheer from the crowd.
He's in a bit of bother here as he battles back and forth to deuce with Jannik Sinner, but two big serves see the Australian through.
Kudermetova 7-6 (7-3) 1-2 Boulter*
Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds
We see flashes of what Veronika Kudermetova can do and why she got to number nine in the world a couple of years ago, she's got bags of talent and a lot of weapons, it's just the inconsistency.
Kudermetova 7-6 (7-3) 1-2 Boulter*
Katie Boulter is just looking to make everything difficult for Veronika Kudermetova.
It looks like a straightforward hold for the Russian but Boulter just keeps coming back.
A powerful crosscourt forehand eventually seals the hold to 30 and the world number 75 is on the board in set two.
*Kudermetova 7-6 (7-3) 0-2 Boulter
Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds
Katie Boulter is looking really composed at the start of this set. She's being very solid and is waiting for the right opportunities to go bigger, she's hitting good quality.
Image source, EPA*Kudermetova 7-6 (7-3) 0-2 Boulter
Katie Boulter has never been to the third round of the Australian Open and she really wants to book her place this time around.
She consolidates that break with a gritty hold for back-to-back games in set two.
Sinner 4-4 Schoolkate*
Tristan Schoolkate is playing some really aggressive tennis here. The Australian is keen to move forward at any opportunity and it's paying off with him winning 11 of the 12 net points so far.
He can't cope with Jannik Sinner's hitting to the baseline and the Italian, after double faulting, wraps up the hold with an ace.
Kudermetova 7-6 (7-3) 0-1 Boulter*
Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds
I like what we are seeing from Katie Boulter though, she is not looking too phased, her body language has stayed extremely positive and she looks very focused.
Kudermetova 7-6 (7-3) 0-1 Boulter*
Well Katie Boulter has done all the right things so far!
An early break of serve is just what she needed after the disappointment of not taking that first set.
Jonathan Jurejko
BBC Sport in Melbourne
Veronika Kudermetova knows how to flatten a mood.
With Katie Boulter an honorary Aussie due to her relationship with Alex de Minaur, the Russian has quietened the court three crowd.
Kudermetova's guttural scream pierces the quiet.
Boulter must take heart from the way she found her way into the rallies and improved as the set wore on.
*Sinner 3-4 Schoolkate
Great judgement from Tristan Schoolkate to leave that passing shot from Jannik Sinner and see it fizz just long of the baseline.
And there's a wry smile from the defending champion as he sends a cross-court forehand wide to gift Schoolkate the hold.
*Kudermetova 7-6 (7-3) 0-0 Boulter
Away we go in this second set. The first one was a rollercoaster, more of the same?