They may have lost their best chance of a home win at the Australian Open in Nick Kyrgios, but Jason Kubler gave the Melbourne crowd plenty to cheer about on Wednesday night.

Kubler, 29, took on No. 18 seed Karen Khachanov on the John Cain Arena in Melbourne, but faced an uphill task having lost the first set to his Russian rival.

And when a break point presented itself at 5-4 down in the second, Kubler showed the true Aussie grit to claw himself level by any means necessary.

Astonishingly, the pair played out a rally that lasted 70 shots, spanning one minute and 37 seconds, before Kubler's shot deflected off the net and dropped onto his rival's side of the court, winning the point.

That rally onset a surge of support behind the Australian, with fans dressed in green and gold barracking loudly for the Brisbane man.

Kubler went on to take the second set 7-5 before losing the next two sets 6-4, 6-2, ending his journey. 

Elsewhere, gallant qualifiers Max Purcell and Aleksandar Vukic have bowed out of the Australian Open on a draining day of despair and delight for the home hopes at Melbourne Park.

Purcell, Vukic and Thanasi Kokkinakis were all forced to return on Wednesday after being sent home after midnight on Tuesday to sleep on unfinished business.

With more rain delaying play for another six hours on day three, the trio had to endure another anxious and lengthy wait before resuming.

While Kokkinakis needed a matter of minutes to complete a 6-1 6-2 6-2 victory over Fabio Fognini to book a second-round showstopper with five-times finalist Andy Murray, Purcell's and Vukic's Open campaigns ended in heartbreak.

When he finally managed to get back on court, Purcell - the reigning Wimbledon doubles champion with Matt Ebden - had no time to settle in against Emil Ruusuvuori.

He was trailing the Finn by two sets to one and entering a do-or-die tiebreaker in the fourth after being unable to convert either of two set points with Ruusuvuori serving at 5-4.

Purcell fended off three match points in the breaker, before fashioning two set points of his own, before finally succumbing 6-4 3-6 4-6 8-6 (13-11) on his fifth match point.

Compounding Purcell's pain was the Sydneysider's decision not to contest the doubles again with Ebden - after the pair lost last year's Open final to Kokkinakis and Nick Kyrgios - to instead focus all his energy on the singles.

Vukic was locked at one set all with fellow qualifier American Brandon Holt when play was stopped for the night on Tuesday with the Australian trailing 4-2 in the third.