Finally, it is mathematically certain that the patience of Rafael Nadal will be rewarded, with the 22-year-old Spaniard, No 2 in the world rankings for a record 157 straight weeks since July 25, 2005, guaranteed to overtake Roger Federer. The Spaniard wasn’t the only one in Cincinnati with something to be pleased about yesterday, as Andy Murray defeated Croatia’s Ivo Karlovic 6-4 6-4 to reach his first Masters final, where he could meet Nadal, who faced Novak Djokovic in the other semi-final late last night.

At the beginning of the year, Federer’s lead over Nadal in the rankings seemed unassailable, but the 26-year-old Swiss has suffered his most ineffectual year since unseating Andy Roddick as world No 1 back in early February of 2004.

Initially, there were the fitness problems with the glandular fever virus, but now the problem seems to be between Federer’s ears and with every week that goes by, the spectre of Nadal is boring deeper into his consciousness. Not only has Federer failed to add to his haul of 12 Grand Slam titles this year, he has won just two relatively minor tournaments: Estoril in Portugal, and Halle in Germany two weeks before Wimbledon. He was thrashed by Nadal in the French Open final and then saw his reign on grass brought to an end when he lost to the Spaniard in a thrilling Wimbledon final. Federer’s Cincinnati demise against the big-serving Karlovic was his 11th defeat of the year - his worst record since the 17 losses he suffered in 2003.

By winning last week’s Toronto title, meaning that he had won prestigious events on clay, grass and hard court in the space of two months, Nadal narrowed the gap to just 275 points. After registering two victories in the Western and Southern Financial Group Masters, the Spaniard guaranteed Federer’s record-breaking consecutive run of 235 weeks at the top of the rankings would end. Now it is just a matter of when.

If Nadal continues his run to secure an eighth title of the year this evening, he will become No 1 when the ATP computer clicks into action tomorrow morning. Even if he loses the final, he will only have to wait an extra week, and if his 32-match winning streak ended late last night in the semi-final against Novak Djokovic, then August 18 will see the Spaniard become the 23rd man to lead the rankings since they began 35 years ago.

This curious situation is born out of the Olympic Games being slotted into the ATP calendar. Both the summer Masters Series tournaments in Canada and Ohio have had to be brought forward to accommodate Beijing and Federer was defending points garnered by reaching a final in the first and taking the title in the second.

Nadal’s confidence after winning his past five events, and the stability of his set-up with coach/uncle, Toni, could not provide a greater contrast with Federer’s state of mind and the Swiss player has lacked any cohesive guidance since parting with Tony Roche 15 months ago. “I guess I’ll analyse and assess my game after the US Open,” said Federer. “For the moment, it’s just all a blur. There are so many big tournaments all in a row and it’s hard. Now there is also the tough trip to China ahead of us, before coming all the way back to New York for the US Open.”

Andy Murray’s ranking may be not quite as high as either, but his form is encouraging. In temperatures of over 90 degrees yesterday, the Scot chose and executed his tactics with almost clinical precision, disheartening Karlovic, one of the biggest servers in the game and delighting a crowd which must have feared a match in which serve would dominate. Instead, Murray produced a sensational array of shots of real invention to which the 6ft 10in Croatian had no answers. Baseline passes from both sides of the court, volleys, athletic returns, drop shots and, most spectacularly, a trio of inch-perfect lobs proved too much for his opponent.

Unlike his quarter-final against Carlos Moya, when Murray took the best part of a set and half to get into the match, the Scot came out of the blocks quickly, chasing down a drop shot and a drop volley to create a break point in the opening game. Karlovic saved it with a typically heavy first serve, and responded by immediately breaking Murray, a raking forehand down the line on a second break point stranding the Scot on the baseline.

Given that only Federer had broken Karlovic’s serve in his run to the semi-final, it looked as though the first set might have already been lost, but that was as good as it got for Karlovic as Murray, helped by several unforced errors, broke straight back. The key to the first set was repeating the feat in the seventh game, the highlight a superb running forehand picked up low and hit across Karlovic as he came into the net. Serving out the set to love saw Murray almost toying with Karlovic, twice flat-footing the Croat from the baseline through sheer accuracy.

A wonderful two-handed service return gave Murray the first of a remarkable eight break points in the opening game of the second set. The Croat fought desperately, knowing that Murray was himself secure on his own service, a point he proved by taking his own serve to love.

Going three break points down in the sixth game was more due to a lapse in concentration by Murray than good play by Karlovic, but the Croat made the third one count. Murray shook himself and broke back with a series of returns that forced Karlovic to dig the ball out from close to his feet. Karlovic’s head dropped, and Murray closed out the match with ease. Tonight he will play the winner of the semi-final between Nadal and Djokovic.

“I played really well, I felt I was hitting the ball really well, but he still had chances so I’m glad I’m through,” said Murray. “I see his serve pretty well, it comes through for me at a nice height, and I think I only got aced five or six times, so I was reading it very well too. I want to play Nadal now - he's the number one player in the world, he's the only top player I haven't beaten, and I think I can do it.”

Going up in the world

- Nadal has won five successive tournaments: the Hamburg Masters, French Open, Artois Championships, Wimbledon and Rogers Cup Masters Series

- When he won his quarter-final against Nicolas Lapentti in Cincinnati it was his 32nd successive victory. The longest unbeaten run is 46 by Guillermo Vilas in 1977

- During this run he has beaten Roger Federer and Andy Murray three times each. His last defeat was in the ATP Masters in Rome in May when he was beaten 6-1 7-5 by fellow Spaniard Juan Carlos Ferrero

- Nadal has been world No2 for 157 weeks. Regardless of what happens now in Cincinnati, he is certain to become No1 on August 18. If he finishes runner-up, he will succeed Federer at the top of the rankings on August 11. Federer had supplanted Andy Roddick in February 2004

How the ATP rankings work: seedings are based on the ATP Entry System, a rolling 52-week calculation based on the four Grand Slams, nine Tennis Masters series events and best five results from International Series and International Series Gold events n Rafael Nadal, watched by girlfriend Maria Francisca Perello, below right, has won seven titles this year and $5,908,074 in prize-money – rival Roger Federer has won two titles and $3,035,141 prize-money