When it comes to their tennis, if Nick Kyrgios is a showman then Karen Khachanov could be called a workman.

Kyrgios uses his abundant natural flair while Khachanov relies on his solid baseline game but both of them are tremendous ball-strikers. In essence, there is not much to separate them in a close match even if their rankings vary.

They two had played just once before, at the now infamous 2019 Cincinnati match after which Kyrgios was hit with the biggest fine in ATP history. On probation since then and close to a big suspension if he errs again, the 24-year-old said he was trying hard to change his attitude but that resolve is tested in almost every match.

As luck would have it, the most stringent test came in a rematch with Khachanov, this time in front of a packed house of home supporters at the Australian Open.

Which Kyrgios would turn up? The sentimental one who has rallied the tennis world for bushfire relief or the emotional one who can’t handle himself in big moments? Turns out on Saturday, we saw a bit of both.

The Australian who survived a four hour and 26 minutes marathon – the longest match of his career – to win 6-2, 7-6 (5), 6-7 (6), 6-7 (7), 7-6 (8) felt like a different player to the Kyrgios we have seen. One who could handle his nerves to play the level of tennis he is capable of more. And it made for an instant classic.

A day after Roger Federer trumped fellow Australian John Millman in another fifth-set third-round epic, Kyrgios was up against the Russian No 2 for a potential clash against Rafael Nadal. A motivated Kyrgios is always a danger and since his probation and the Australia bushfires, he has seems to be more responsible than ever.

He started the match with a self-assured calm, taking the first set with two breaks of serve despite needing a medical timeout at 5-2. The 23-year-old Russian put up better defense in the second and a tie-break was required, with both players unable to convert the only break-point chance. Kyrgios took it with a mix of stunning points and looked comfortably placed for an early finish. His lethal serve was firing, the forehand was spinning and the drop shots were a delight as always.

Just like in his last match against Gilles Simon, he led by two sets and a break before a momentary lapse in focus. His serve was broken for the first and only time in the match, he was unable to convert his first match point in the tiebreak and he began to leak errors.

The fourth turned out to be titanic tussle within the much bigger battle. There were no breaks of serve, Khachanov committed just two unforced errors (to 11 winners) and Kyrgios hit 23 winners (to 14 unforced errors) as both players upped the ante.

A crucial moment in the match was when Kyrgios saved two break points at 3-3 and then lost it with the umpire after being given a time violation. To be fair, this one time he was not to be completely blamed for the error.

He had hurt his hand whole diving full-tilt for a volley and was bleeding, which he stemmed with a towel. He refused to let the ball kid take the soiled towel and the subsequent delay prompted a time violation from the chair which was vociferously contested. The word ‘stupid’ was thrown around, as was a racquet and the tirade continued even as his hand was treated.

This is always dangerous territory with Kyrgios and when Khachnov saved a second match point in the tiebreak after a tight fourth, there was a sense of impending implosion from the volatile Australian.

Let’s be honest, Kyrgios has combusted for much less and here he was – two wasted match points, a bleeding hand, arguing with the umpire and completely knackered. But somehow he found a hidden reserve of willpower and energy and persevered.

After dropping the third set in the last match against Simon, he had shown that he has the ability to play percentage tennis and stay in rallies without letting impatience or flamboyance creep into his game. He had then admitted he was on the verge of going “to a very dark place” before refocusing.

To do that in a much more physically and mentally intense match was as impressive as it was astonishing.

There was no break point in the deciding set and it all came down to the 10-point shoot-out. Once again, Kyrgios found himself staring at the end of a barrel... 8-7 down on Khachanov’s serve.

And then came the best strike of the shot-studded match, a bullet-like backhand down the line to level up 8-8. It was a moment of inspiration from the man who has ‘Inspire Others’ tattooed on his arm. The stunner seemed to change the momentum and Khachanov committed two errors on his backhand to fold.

Kyrgios fell to the ground, acknowledged the crowd and his opponent but was virtually speechless in the on-court interview.

But the numbers did the talking for him and the match that was decided, in the end, by the sheer effort from a player who had the tendency to tank in tight spots. Four of the five sets went to tiebreaks and the margins were slim – 7-5, 8-6, 9-7 and 10-8. He had 97 winners (to 75), 33 aces (to 21) and won 50 points of 71 at the net (to 41/50).

It was a complete Nick Kyrgios Experience but with a plot twist ending – going through a the whole gamut of emotions while not giving up. No matter how the fourth-round clash against Nadal goes, this match will go down as one of the mercurial Australian’s very best.