Time ran out for one brave finalist here on Sunday night but against all well-reasoned forecasts, it was not Andy Murray. In what was probably his most extraordinary win over Novak Djokovic since he won the first of his three grand slam titles – in New York four years ago – the prince of perversity, riding a wave of adrenaline after one of the toughest weeks of his career, beat the man whose crown he had snatched away so impudently in Paris a fortnight ago.

In so doing Murray confirmed he is not only statistically the best player in the world, but is rightfully so in every way. He may remain there well into the summer of 2017.

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In beating Djokovic 6-3, 6-4 in an hour and 42 minutes to win his first ATP World Tour Finals title, the Scot secured the world No1 spot at the end of a long and glorious year, and confounded pessimists who predicted the rigours of the past week – not to mention the previous three months – would drain him of the will to win. “Obviously it’s a very special day,” Murray said. “I am happy to get the win today and finish the year as No1. I never expected it.”

There was some justification for the prognosis, given Murray had reached his fifth final in a row after spending nearly 10 hours on court in four matches over the past six days, compared to his opponent’s six hours and 33 minutes, the last 66 of those arriving against a washed-out Kei Nishikori on Saturday night, in the shortest match of the week. That followed Murray’s three hours and 38 minutes against Milos Raonic – the longest match of the tournament. But, as Macbeth said (apparently): “If it were done when ’tis done, then ’twere well it were done quickly.”

Whatever notions Djokovic had expressed beforehand about respecting Murray’s integrity and fitness, the Serb looked increasingly woebegone as he failed to break the resolve of an opponent over whom he held a 24‑10 career advantage.

Murray, who had sweated up beforehand, like a fighter getting ready for a world title shot, no doubt had a shaking hand on his racket, double-faulting twice in the first five minutes, although he also banged down his fastest serve of the tournament, a 132mph ace.

With the thought buried in his psyche that time was not on his side, it was clear he was going to throw a few haymakers. Djokovic, 19-0 against Murray when taking the first set, imposed his will early, and looked comfortable holding to love for the second time.

He was sharper and more hurtful with ball in hand in the early exchanges and Murray could not take a point off his serve in the first 20 minutes.

However, he got two good looks at it in the sixth game, and was delighted when Djokovic butchered the easiest smash of the week for a third deuce point. But Murray hit long twice and the moment passed.

Now, though, it was Djokovic who struggled more. Murray, peppering the backhand, cracked his defence with a teasing slice that Djokovic could not get over the high side of the net, and the break was his.

When he forced another anaemic, off-balance reply from Djokovic after 46 minutes. Against most predictions, he could set about building on his lead.

Djokovic, of course, had scored five of his 24 wins over Murray in their 34 matches after losing the first set, and he would have to do so again. He would not go away without a fight – he never does – but giving up four break points at the start of the second set was no way to launch a fightback. When Murray forced a limp backhand from him, the arena rose in anticipation of a famous victory.

The strategy, the predictions and expectations were all being turned upside down. The supposedly fresher Djokovic was heaving between points; the supposedly exhausted Murray was rejuvenated. By the time Djokovic belted a weary backhand long to hand Murray a second break for 4-1 after a mere hour and a quarter, Djokovic seemed to have lost his way.

However, one of the game’s enduring gladiators broke back in the sixth game then held to love to inject a measure of tension into the contest. A 33-shot rally lit up the eighth game, but Murray stayed solid and Djokovic had to hold to stay in the match. He did so, to 15, and handed the sword of fate back to Murray.

Murray stepped up to grab a little bit of history and could be excused for trembling, as he had done at the start – as he had done when stepping up to serve out against Djokovic to win Wimbledon in 2013.

Djokovic saved two championship points but his own hand shook surely as he thrust his closing forehand long. The crowd were on the very edge of civility, but understandably so.