IT was fitting that, in the place he trains so hard for extended periods of the year, Andy Murray fought out a gruelling physical battle to defeat David Ferrer in the final of the Sony Open in Miami and become the new world No.2.

The Scot showed just why he has leapfrogged Roger Federer by coming through a two hour, 44 minute test of body and mind as he won 2-6, 6-4, 7-6 (7-1) to claim his first Masters title since October 2011 in Shanghai.

Many have spoken for some time of Novak Djokovic and Murray having taken over from Federer and Rafael Nadal as the leading rivalry in the men's game, and the computer ranking system is finally acknowledging that.

Murray had earlier cautiously downplayed the potential benefits of returning to No.2 for the first time since September 2009 – it could put him in the opposite half to Djokovic, Federer and Nadal, the seven-time Roland Garros champion who, with so many points to defend in the next two months, is almost certain to be seeded fifth in Paris this year, at forthcoming tournaments on the clay. Equally, it could land him in the same quarter as the Spaniard.

There is no doubt, though, that Murray will take considerable satisfaction from his step up in the rankings which was earned as a result of one of his most hard-earned victories against Ferrer yesterday. "It was such a tough match," said Murray. "It could have gone either way. Both of us fought as hard as we could. We were both struggling physically at the end and I just managed to come through."

Ferrer had already underlined once again that he is so much more than just a clay-court expert with his run to the final and he will replace Nadal as the world No.4 in today's rankings following his efforts on the Florida coast.

Yesterday's final was one of the earliest on the ATP tour for some time, as a clash with basketball TV coverage meant the final was pushed forward to 11:30am local time. It was hardly ideal for Murray, who is often not at his best in the morning.

The Scot struggled to find his rhythm and quickly fell 5-0 down as Ferrer was in the zone from the start. Murray reduced the deficit to 5-2 but then gifted the set to Ferrer, who only had to hit two returns to break for the third time, with Murray double-faulting twice and tamely hitting two forehands into the net.

Murray hit back in the second set, though, as he began to find his range, with more errors being forced from Ferrer. The Spaniard hit wide to give Murray the break for 2-1 but he later lost it when, following an exchange with umpire Cedric Mourier about the time violation rule, he netted a drop shot on break point down at 4-4. He quickly regrouped, though, and broke back straight away before serving the set out comfortably to level the match.

The first six games of the decider all resulted in breaks of serve – remarkably, a sequence of eight consecutive games in which the server was unable to force home his advantage – Ferrer finally held for 4-3 and Murray followed suit. Murray then broke once more to lead 5-4 when Ferrer netted a forehand. Murray's slow and laboured walk to the chair for the changeover suggested that there may be more drama yet to come, though.

So it proved. Murray faltered again and netted when facing a break point at 40-30 and Ferrer, having held for 6-5, earned a match point on Murray's serve when the Scot volleyed wide.

Murray saved it when, during another extended rally, Ferrer stopped mid-point to challenge when he thought Murray's forehand had gone long. Hawkeye showed that it had caught the line, Murray held and the match went to a deciding tiebreak.

Ferrer faltered early, hitting a number of unforced errors and Murray was firmly in control at 5-1 when Ferrer fell to the ground with cramp after another long point. It is unusual to see the 31-year-old, who is regarded as one of the fittest players on tour, struggle with fitness. The Scot only needed one of five championship points at 6-1 as he hit a backhand winner to claim his 26th career title and a hugely satisfying victory.

"A couple of years ago, I would have lost that match," said Murray. "I was up a break four times in the third set and I let him back in with poor shots. Being 5-0 down in the first set wasn't the best way to start either. But in the third set I chased every ball down and made it as difficult as possible for him."

Murray should remain at No.2 in the rankings for a considerably longer period of time than the four weeks he spent there previously, as Federer is not scheduled to compete again until he defends his title in Madrid at the beginning of May.

While winning grand slam titles will always be the main goal for Murray, his new ranking underlines his credentials as one of the leading players in the world. It is this appeal which has resulted in him being linked with a potential Asian Tennis League series to be held in December.

He is reported to have been offered more than £3m to sign up, although it is understood that there are still further talks to be held before he confirms his appearance. It will be intriguing to see how he would work a potential exhibition series around his regular off-season training block.

Murray will now remain in Florida to prepare for the clay season, which begins in Monte Carlo in two weeks' time, and work on his serve under the watchful eye of Ivan Lendl. It is the reason why he has decided to skip the Davis Cup match between Great Britain and Russia in Coventry this weekend.