Jonathan Jurejko
BBC Sport in Melbourne

Hmmm the plot thickens.

The physio has just been called for Kudermetova.

She waits patiently in her chair while Boulter gets up and goes for a chat with her coach Biljana Veselinović.

Then the Brits whacks down some serves and forehands from the baseline to keep loose.

We're up and running on Rod Laver Arena.

Tristan Schoolkate will be hoping to get on the scoreboard first against Jannik Sinner, with the Australian serving first to get us under way.

*denotes next server.

Ah, Veronika Kudermetova has called for the physio after losing a third game in a row.

She is rubbing her chest and that is clearly bothering her. Let's hope she can continue here.

The comeback is on!

From 5-1 down Katie Boulter moves to 5-4 with a comfortable hold of serve and looks to have a bit of a spring in her step again.

Katie Boulter looks like she's really found a bit of flow here.

There's plenty of British support on Court Three but it seems she's also got the support of the Aussie crowd.

Her Australian fiance Alex de Minaur is watching on from the stand having won his second-round match earlier on.

Well how big could that prove!

Katie Boulter saved three set points then took her chance on her first break point to prevent Veronika Kudermetova taking the opening set.

More like it from Boulter and the crowd respond.

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds

It's really good tennis here from Katie Boulter, she's made more returns off the first serve in this game. It looks like she's settling into the match and starting to find her rhythm.

Veronika Kudermetova just struggling to get it over the line here. She's hit an ace and a couple of good forehands but Katie Boulter isn't going down so easily.

Kudermetova misses her third set point before Boulter sends a lovely passing forehand down the line and will have a break point opportunity.

Defending champion Jannik Sinner said he was "happy" with the reception he received from the crowd after making a winning return to the Australian Open on Tuesday amid his ongoing doping case.

World number one Sinner, who claimed his first major title in Melbourne last year, was competing at the tournament for the first time since he failed two doping tests in March.

The 23-year-old Italian, whose doping case will be heard at the Court of Arbitration for Sport (Cas) in April, began his campaign with a 7-6 (7-2) 7-6 (7-5) 6-1 win over Chile's Nicolas Jarry.

"I was curious to see how it was. You never know what's happening," Sinner said of the reception on Rod Laver Arena.

"I was happy about the crowd. It was a very nice crowd. There were some for my opponent and some for me. It was a nice atmosphere"

That may be the case but the atmosphere today could well be stacked pretty heavily against him as he takes on home player Tristan Schoolkate.

Image source, Getty Images

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds

Katie Boulter will be a little bit miffed of what's happened in this set because it just went away a little bit too quickly. Hats off to Veronika Kudermetova she's the one that's made things happen and has served extremely well.

A big roar as Katie Boulter holds her serve and there's a shake of the head from the Brit as she heads back to her chair.

She's not happy with how this set has gone.

Veronika Kudermetova will serve for the opening set.

Veronika Kudermetova has got Katie Boulter rattled.

A double fault is followed by a forehand into the net but the Brit varies the shots in the next rally to draw back level at 30-30.

She needs a hold here to prevent Kudermetova completely running away with this set.

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds

Veronika Kudermetova is not giving Katie Boulter a lot of time to settle on the ball, she's being very aggressive and she's served well so far, it's getting Katie on the back foot straight off at the start of the point and then she's got the skills to construct the point really well.

Jonathan Jurejko
BBC Sport in Melbourne

Image source, BBC Sport

Good things come in three, right?

We’re back on court three, where Emma Raducanu and Jack Draper both won their first-round matches.

Katie Boulter is aiming to make it a British hat-trick in this picturesque 3,000-seater arena where blue court runs into blue sky.

But, as you know, she has work to do to keep the healthy British contingent happy.

Katie Boulter works herself an opening, getting out to 0-30 on the Veronika Kudermetova serve. But it's clinical stuff from the Russian and she quickly recovers to get to 40-30 with an ace.

Boulter's forehand slams into the net and that's impressive from Kudermetova, from 0-30 to take the hold and put herself on the brink of winning the opening set.

Image source, Getty Images

The night session on Rod Laver Arena will be getting under way very shortly with Jannik Sinner continuing his title defence bid.

The world number one will have the home crowd against him as he takes on Australian wildcard Tristan Schoolkate.

Schoolkate is ranked 172 places lower than Sinner and has only two tour-level match wins to his name, so it would be massive if he can pull off an upset here.

Leon Smith
GB Davis Cup captain on BBC Radio 5 Live and BBC Sounds

Veronika Kudermetova is showing extremely good body language and intensity, that is something that Katie Boulter can match.

Boulter is also high in confidence having played at really high level at the United Cup. She is ranked in the low 20s for a reason and is playing great tennis, she's such a good competitor which we saw the other night.

Image source, Getty Images

It's all square on 1573 Arena. After winning the opening set tie-break, Joao Fonseca has lost the second against Lorenzo Sonego.

That ends the Brazilian teenager's 23-set winning streak.

The Italian, ranked 57 places higher than Fonseca, broke early and struck again at 5-3 to draw level and he will head into the third set with the momentum on his side.

Veronika Kudermetova has Katie Boulter scrambling all over the court and her good start has turned into a brilliant one.

For Katie Boulter, it's gone from bad to worse as she concedes the double break after being dragged into the net before Kudermetova pumped one past her.

Bit of a wobble there for Veronika Kudermetova but opportunity missed for Katie Boulter as the Briton sends her forehand long and Kudermetova consolidates that break of serve.