Perfect chance for Andy Murray to prove he is the best of the best

Andy Murray and Juan Martin del Potro are merely the fourth and fifth finest players in the world, the rankings computer assures us. Yet it would be no surprise or anti-climax to find them paired in a grand slam final, because between them and the trio above there is virtually nothing to choose. Perm any two from Murray, Del Potro, Roger Federer, Rafael Nadal and Novak Djokovic, and you have a potential classic.

This opener was not one of those, in truth, largely because this round-robin format draws the venom from group matches, but it did offer the chance to gauge how the Argentine is coping with his US Open triumph. Very averagely indeed would seem the answer.

That September night, he trailed two sets to one before blowing the Fed out of the water with the most destructive missile known to tennis - that flat forehand that targets the ball at the lines at breathtaking speed.

The problem for the Lurch lookalike, Earth's oldest-looking 21 year old, is that young chaps need recovery time after winning that first major.

Even Pete Sampras and the Fed vanished for a bit, while only now, almost two years after his Australian Open breakthrough, has Djokovic recovered top form. Achieving an ambition cherished and nurtured since almost infancy is a very tough thing to handle.

Murray's psychological problem is, of course, the opposite. He has been unlucky in Grand Slams, continually meeting players in the form of their lives. But the longer he goes without breaking his duck, the more crushing the weight of expectation becomes.

This event is not a major, but with the leading eight players of 2009 gathered - seven, anyway, with Robin Soderling replacing the injured Andy Roddick - it comes next in prestige and ranking points, and Murray has an excellent chance.

After this defeat, Del Potro has virtually none. Short of court time since the US Open, and struggling to adjust to megastar status, his concentration waned at either end of this match and no one can afford such laxity against Murray.

The very first point set the tone, with the Scot defending nimbly against that brutal forehand from the baseline before teasing an error on the forehand volley. So vertiginous was Murray's early superiority that at 0-3 Del Potro developed a nosebleed, and thanks to the TV director for the close ups of the blood-caked swab emerging from his left nostril. Quite a digestif after a large Sunday lunch.

Only when Murray needed two points to win the set 6-0 did the Argentine come over a touch Mandelsonian. Proving that he's a fighter not a quitter, he held serve, then broke and held again before Murray edgily closed out the set 6-3.

All the momentum was with Del Potro, however, and when he took the second by the same score, a thrilling decider seemed imminent. But Murray had other ideas. His prodigal first serve returned, the unforced errors departed, and faced with his opponent's consistency and guile Del Potro became fatigued. Consecutive double faults gave Murray match point, and this he took by defending superbly until the opening for a forehand sucker punch appeared.

Murray is beautifully placed to win this tournament. Probably the world's best player both indoors and over best of three set matches, here he has an ideal surface (the low bounce makes his slices hard to control), not to mention 17,000 raucous home fans behind him. I make him joint favourite with Djokovic, especially after Roger Federer made a sloppy start against Fernando Verdasco before winning in three sets 4-6, 7-5, 6-1 in the same group as Murray last night.

Yet even if the Scot does take this title, it won't answer the question Del Potro categorically resolved in New York. "London's Calling" was playing in the O2 Centre as he walked on court yesterday, but with January's Australian Open the next chance to lay that pesky grand slam ghost, Melbourne's Calling must be the tune playing on a loop in Andy Murray's head.