Australian Open - Nick Kyrgios survives five-set marathon with Khachanov, will face Nadal next

The 24-year-old put in another box-office performance - at one point raging at the umpire after missing an unnecessary tweener - to see off world number 17 Khachanov after a titanic struggle, and will face 19-time Grand Slam champion Rafael Nadal for a spot in the quarter-finals.

Russian Khachanov, a five-set winner against Mikael Ymer in round two, fended off match points in sets three and four but he was unable to fend off a third, sending a backhand wide in the final-set tiebreak, prompting Kyrgios to collapse in elation and the Melbourne Arena erupt in euphoria.

"That was crazy. That was insane. I've got no words. You guys are unbelievable here," said Kyrgios on court after the match.

"I was losing it mentally a bit, losing the third and fourth after having match points it wasn't easy. You guys willed me all the way, I thought I was going to lose."

The Australian, whose best showing at his home Grand Slam was a quarter-final appearance in 2015, was coasting in the first set – leading 5-2 – when he had to call for the trainer. Some treatment seemed to arrest an apparent hamstring strain but sets two and three were far tighter affairs, with Kyrgios and Khachanov sharing a tiebreak each to send the match to a fourth set.

The firebrand Australian, leading 4-4 30-0, botched an unnecessary tweener and in doing so cut his hand, leading Kyrgios to try to stem the bleeding with a towel and prompting an unaware umpire to hand the 24-year-old a time code violation; an incensed Kyrgios berated the official, calling them "an idiot" and asking whether they "were stupid".

The 23rd seed steadied himself following that outburst but could not halt the charge of his 23-year-old opponent, who sealed a fourth-set tiebeak and, in doing so, ensured a fifth and final set. But it was Kyrgios who would prevail, winning a five-set match for the first time in his career having led two sets to love.