It's Jack Draper who gets up and running first in the fourth set, coming out on top of 25-shot rally - the longest of the match - en route to the a nervy hold.

Abigail Johnson
Commentator on BBC Radio 5 Sports Extra and BBC Sounds

The competition on a cold Court 14 is very much alive.

I don't think we touched enough on the fact that Harriet Dart is one set away and has been for a while from equalling her best Grand Slam run, has never been to the third round at the Australian Open, has twice made that round at Wimbledon but has never gone further.

What a final set this is turning into.

Donna Vekic goes after an immediate response on Harriet Dart's serve and breaks the Briton to 15 to restore parity in the decider.

Which way this one is going to go is anyone's guess.

A double fault from Arthur Cazaux and it's advantage Jacob Fearnley, who takes that third set in just over half an hour.

The momentum has shifted and it's looking very, very positive for the Briton.

Image source, Reuters

Bang! Jacob Fearnley takes advantage of a weak second serve from Arthur Cazaux, flinging back a wicked forehand winner to bring up two set points.

Here we go!

Harriet Dart makes the breakthrough in the deciding set, taking the second of her three opportunities with a forehand winner.

The lucky loser never allowed her head to drop as Donna Vekic reeled off those seven consecutive games and now the pressure is back on the 18th seed.

Image source, EPA

Jacob Fearnley is well on his way to this third set after riding out another service game. What a boost this would be to his confidence.

The momentum swings again!

Harriet Dart goes from defending a break point to eyeing three of her own as Vekic tightens.

Gigi Salmon
BBC Sport tennis commentator on BBC Radio 5 Live and BBC Sounds

Thanasi Kokkinakis doesn't look that happy, he looks slightly surprised, he's going more and more damage to the body but he plays on and he has the lead over the 15th seed.

Take that! Thanasi Kokkinas was on the brink during the middle of that set, but he slams down a huge ace to win the third set.

What does Jack Draper have left? He's going to have to go the distance if he's to have any chance of booking his place in the third round.

Image source, Getty Images

That's a really big hold for Harriet Dart, bringing an end to a run of seven games for Donna Vekic and giving herself a platform in the final set.

Let the race for the finish line commence.

Jack Draper catches his opponent off guard with a crafty body shot to pull level at 30-30, but he's left shaking his head in disappointment after a forehand miss.

Set point, Kokkinakis.

Harriet Dart arrows a superb backhand down the line to edge ahead at 30-15, but Donna Vekic continues her push for victory by setting up her latest break point.

Big moments ahead in this match. Dart finds a first serve for deuce.

That last service game really got the crowd behind Thanasi Kokkinakis and there's an even bigger roar now as he gets the break.

Jack Draper needs something special now to stay in the set and keep the celebrations of the Australian fans at bay.

Coco Vandeweghe
Former two-time Grand Slam semi-finalist on BBC Radio 5 Live and BBC Sounds

Both of these players do not want to look at the stats, it was not pretty tennis and unfortunately that is sometimes the way the cookie crumbles at these Grand Slams.

Harriet Dart just needs to regroup and forget, it's a one set shootout and she needs to go back to basics and not allow Donna Vekic to feel comfortable again. She needs to use these conditions to her advantage and make Donna work for every point.

Now then, what's this? After a mammoth struggle in his last service game, Thanasi Kokkinakis has got himself two break points.

A lapse in concentration from Jack Draper perhaps?

Donna Vekic continues her streak of games with a straightforward hold to begin the third set.

This is a must-win service game coming up for Harriet Dart now, just to give her something to build on. It's been one-way traffic for a while.

Arthur Cazauz saves another break point and finally gets himself on the third-set scoreboard.

But there's no stopping Jacob Fearnley on serve as he blazes down two aces en route to a love hold.

There's an eruption of noise as Thanasi Kokkinakis, finally, gets the job done.

That game took over 15 minutes and the Australian celebrates the hold by crouching down and directing a couple of fist pumps towards the crowd.

Image source, Getty Images

Abigail Johnson
Commentator on BBC Radio 5 Sports Extra and BBC Sounds

Not a lot about the play in this second set has been particularly clean and you can totally understand it with the late night conditions with the wind which picks up and drops and messes with proceedings.