In November, Jannik Sinner faced three match points against Novak Djokovic with Italy’s Davis Cup hopes on the line. Defeat would have spelled the end in the semi-finals, and with Djokovic looming over the baseline, primed for his next return, Sinner stared at a near-impossible task. Instead, the 22-year-old held firm. He saved all three match points behind brave serving and a rock-solid backhand, denying Djokovic. Sinner went on to claim his second victory against the world No 1 in as many weeks, following his win in the group stages of the ATP Finals.

It may have just been one game and one hold from 0-40 down, but that five-minute spell in Malaga at the end of last season may prove transformative in the young career of Sinner. The Italian not only survived but steered his nation past Serbia and into the Davis Cup final, where he again won the decisive match against Australia to lift the trophy. On Friday, in the Australian Open semi-finals, the Italian will face Djokovic for the fourth time in three months as he aims to reach his first grand slam final. Sinner has won two of their last three matches and, this time, the odds are considerably shorter than when Djokovic held those match points.

Djokovic’s Australian Open record - where he has won 33 matches in a row and is this week aiming to win his 11th title - weighs heavily over the semi-finals, but in terms of current form rather than history, it is Sinner who arguably arrives as the favourite. The 22-year-old’s outstanding run at the end of last season - where he was Djokovic’s biggest rival - meant that expectations had risen even higher ahead of the opening grand slam of the year, yet the fourth seed has delivered.

Along with Djokovic, Carlos Alcaraz and Daniil Medvedev, reaching grand slam semi-finals is now the bar and Sinner has took to the Australian Open as if the earlier rounds were simply the precursor to the main event. Of the four semi-finalists (Medvedev will face Alexander Zverev after the German stunned Alcaraz), he is the only player yet to drop a set and his progress has been as smooth and composed as his crisp, clean ball-striking.

Sinner arrived at the Australian Open having elected not to play a warm-up tournament in Brisbane or Adelaide following his efforts at the end of last season - it was a risk but Sinner was still able to coast through his opening two rounds while playing himself into form. Timing is a huge part of the grand slams, knowing when to peak and how to save yourself is an art Djokovic has mastered, and Sinner has worked his way through the tournament like he knows he belongs in the final four.

And yet it will still only be his second semi-final at a grand slam. The first came at Wimbledon in July and ended in an underwhelming straight-sets defeat to Djokovic. Sinner made far too many errors, particularly on his unusually erratic forehand, for the match to be competitive. He ironically produced a better match the year before, aged 20 and ranked 13th in the world, after leading Djokovic by two sets in the quarter-finals. While Djokovic admires Sinner and regularly practices with the Italian, that was the moment where he knew that he would one day be a real threat. That much was clear with how Djokovic ruthlessly dispatched Sinner in their Centre Court rematch 12 months later.

Sinner’s game has gone up another level since that Wimbledon defeat, firmly establishing himself in the world’s top four thanks to his red-hot form at the end of last season. The difference now, of course, is Sinner must now do it over best-of-five sets. And since the start of 2020, only three players have managed that in Alcaraz, Medvedev and Rafael Nadal.

In Melbourne, Djokovic has shown glimpses of vulnerability while still underlining how hard he is to beat over long distances. The 36-year-old has dropped a set in three of his five matches through to the semi-finals, against Dino Prizmic, Alexei Popyrin and Taylor Fritz, but every time the 10-time champion has responded to win the third. By the fourth, his opponent found the life had been sucked out of them, their legs drained, after realising how hard they had fought and how far there still was to go.

Sinner has the game and the ability to take one of the first two sets against Djokovic, that should be clear to both players. But what will make the difference in taking the next step from contender to champion is how Sinner reacts when the match turns into a marathon battle of mentality and physicality as much as skill. Sinner’s progress has been one of incremental improvement and learning from past defeats. The moment will come: how Sinner responds will reveal how close his grand slam breakthrough is to arriving.