But, as he fought tooth and nail last night, taking two hours and 28 minutes to force his way past Fernando Verdasco in the second round of the BNP Paribas Masters in Paris, he looked like a man willing to sweat blood to chase down Novak Djokovic at the top of the pecking order.
He kept himself in the race but he was hanging on by his fingertips in the second and third sets.
On paper, the match-up looked a little tricky but still eminently winnable. After all, the two had played each other a dozen times before and Verdasco had won only once and that was years ago in 2009.
He may have threatened from time to time – the Wimbledon quarter-final of 2013 was not for the faint-hearted – but he could not get the better of Murray on any surface.
Better still, coming into the Paris tournament, Murray was on a 15-match winning roll while Verdasco approached last night’s encounter having lost six of his last eight matches.
Surely this, then, was Murray’s match to lose. Alas for the Scot, professional sport is seldom that cut and dried. It had all looked so easy in the first set: Murray was in charge and Verdasco seemed to know his place.
After a few games to get used to the court and the conditions, Murray began to hit his stride, forcing the issue with his backhand and pulling the Spaniard around like a puppet on a string.
That put pressure on the Verdasco serve and a couple of points later, the Scot had taken what turned out to be the decisive lead. He was a set to the good in just 32 minutes. This was the sort of performance the potential world No 1 was hoping for. But it was not to last.
The second set was one of those white-knuckle rides that really ought to come with a government health warning. Verdasco kept to his game plan, such as it was (presumably the nine double faults he racked up over the three sets were not on the blueprint) while Murray went on the defensive. And the further he stood behind the baseline, the more opportunities he gave his opponent.
Two breaks of serve each had the nerves fraying on both sides of the net, with Murray’s patience wearing dangerously thin, while the tie-break was a mirror image of the rest of the set: Verdasco struck first and took a 5-1 lead and then Murray fought back. Three sets points went begging for the Spaniard but on the fourth he was not to be beaten as Murray dumped a backhand in the net.
Now Murray was looking weary and grabbing his hamstring when his shots went astray. Even his early lead in the third set did not last very long – Verdasco broke back immediately – and he could not find a way to put any concerted pressure on the Spaniard.
Normally, Murray can tear an opponent’s confidence to shreds with his return game but last night he could not plant that seed of doubt in Verdasco’s mind. When he broke serve, he could not hold on to the advantage and, even with the world No 46 chucking in all those double faults, Murray could not put a stranglehold on his returns.
No matter, he took the early lead in the final set. At 2-0 up, surely he was not going to let Verdasco back into it – but he did. Back came the Spaniard and, as the underdog fighting the world No 2, he had the crowd on his side. The Paris crowd are a notoriously difficult bunch to please and the more Murray tried to rouse himself and force himself on, the more they booed him.
When Murray faced two break points at 5-5 in that third set, it did appear that his hopes of catching Djokovic had gone but back he came again. And once he had averted the danger, he broke Verdasco to love and closed out the match. Murray and his ranking ambitions were still alive and kicking. Now he just has it all to do again today against Lucas Pouille.