Melbourne Park, 12 December 2012 | James Hunter-Smith

Up 4-0, 40-0 in the fifth set, Nick Kyrgios finally found the momentum he’d been looking for. He and opponent Matthew Barton were locked in a 33-degree dogfight during their Australian Open 2013 Play-off quarterfinal, but the 17-year-old wildcard was well on his way to yet another upset.

That was before it all went wrong.

After more than three hours of gruelling tennis, Kyrgios cramped – and cramped badly. His commanding lead was cut to 30-40, 4-1 when Kyrgios – whose agility and movement was all but gone — fell to the ground, grasping his leg. His trainer and the chair umpire helped him on his feet but he was unable to return to the court, forced to forfeit the five-set epic in heartbreaking fashion.

The final score read 6-7(3) 6-3 3-6 7-6(4) 4-3 (ret) in favour of Barton after three hours and 44 minutes on court.

It was a dramatic ending to a dramatic match, one that the 100-odd spectators rode from the opening serve.

Catch up with all the latest scores from the Australian Open 2013 Play-off here.

Twenty-year-old Barton, who sits as the No.8 seed in the play-off, had no problems conceding his mental strength was tested going into the fifth and deciding set.

“Physically I feel alright, I could’ve kept on going, but just mentally it was tough,” he said.

“To lose that fourth set in such circumstances, having so many opportunities, it’s tough. But luckily physically I could hang on.”

While Barton endured a major mental slump, he’s sure got a good way of hiding it. It was a match brimming with major ups and downs, but the Sydney local demonstrated a composed and cool demeanour throughout.

“I definitely don’t show too much emotion out there, I try and keep it inside of me which helps a lot, and which is different to Nick (Kyrgios) who is all outside. But I just tried to hang in there and mentally it’s tough but I’m just really happy in the end,” he said.

The players, battling for a wildcard entry into the main draw of Australian Open 2013, could not be separated in the opening set. The men traded service games, slogging out points via booming groundstrokes from deep in the court.

Kyrgios’ serve was particularly potent and caused major headaches for Barton early. On serve at 4-3, Kyrgios unleashed a monster ace down the tee flying well past his opponent’s racquet. But Barton wasn’t the only one concerned about the lightening serve – a particular lineswoman had issues of her own, ducking at the last second to avoid a nasty bruise on her arm.

With the scores locked at 6-6, Barton raced to a 4-1 lead in the tiebreak. Kyrgios kept fighting but it wasn’t enough, as a shanked backhand into the net allowed a steady Barton to close out the tiebreak 7-3.

Kyrgios was on the front foot in the second, using the sidelines with superb touch and accuracy and pushing Barton around the court with ease.

A mounting tally of questionable line calls eventually found Kyrgios fed up, as a backhand sent sailing into the net prompted him to slam his racquet into the Plexicushion with brute force, bouncing it level with the top of the fence.

It wasn’t long, however, until the 17-year-old got the first break of the game, celebrating with a stone-cold glare into Barton’s eyes, a fist pump and a viscous “Yeah!”, much to the displeasure of the chair umpire.

Check out all the photos from the Australian Open 2013 Play-off here.

Kyrgios later levelled the match at one set a piece but that only fuelled Barton to push harder. He was being sent on a wild goose chase early in the third, frantically chasing down balls from sideline to sideline, outstretched and on the back foot, but managed to save the points. His work ethic eventually paid off, breaking Kyrgios early and racing to a 5-2 lead.

Kyrgios was able to hang on momentarily after holding his serve but a pair of shanks allowed Barton to seal the third set 6-3.

More dubious line calls continued to aggravate both players in the fourth as service games were exchanged in identical fashion to the opening set. Kyrgios found himself down 0-40 at 2-2 and staring down the barrel of a quarterfinal exit but after some more sublime first serves followed by a swift backhand slice, he was able to hold.

With scores locked at 5-5 and the match in the balance, no player could break away. Barton had yet another two break points at 15-40 and was painfully close to serving for the match, but Kyrgios again held his ground. Neither could take advantage, as the game alternated between deuce and advantage, both men saving themselves via stunning winners down the line often barely clipping the line.

The match was yet again forced into a tiebreak as Barton began showing signs of fatigue after quickly falling to 0-3. But it was the 20-year-old who this time proved he could claw back, levelling the score at 4-4 before Kyrgios blasted three winners – two forehands down the line and one cross-court – to send the match into a fifth set.

Only 15 minutes later and Kyrgios had the win well in his grasp, looking to score his second major upset in the play-off. Up 4-0, 40-0, he looked all but home.

That was, of course, until disaster struck.

Cramps forced him off the court and ultimately out of the tournament, a likely result of his 17-plus hours on court over 11 matches in the past nine days.

It was a cruel result that eventually came down to a survival of the fittest, one that vaulted Barton over the line.

So, with a semifinal match on Friday Barton is only two wins away from his maiden Australian Open main draw appearance. Not that it’s on his mind, however.

“One game at a time,” Barton laughed.

“I’m not really thinking about that too much, I’m just trying to work hard and just do the little things right, and hopefully all that stuff will take care of itself.“

And how do you recover from a five-set slogfest in the punishing Melbourne summer sun?

“I’ll just get into a cold shower, into an ice bath or something and recover the body and hopefully I can be right for whoever I’ve got next,” Barton said.

With Friday set to be another 30-degree scorcher, perhaps make that a double ice bath.