SHANGHAI: A relaxed Roger Federer says achieving the year-end number one ranking would be a bonus after a successful season but insists he has already achieved his goal, which was winning back top spot.

The Swiss great, playing his first tournament on Tour since the US Open, crashed out in Saturday's semi-final of the Shanghai Masters to Britain's Andy Murray, who also beat the 17-time Grand Slam champion in the Olympic final.

The 31-year-old, who became number one again after his Wimbledon triumph, will Monday start his 300th week at the top but faces a battle to hang on against a charging Novak Djokovic.

“I would love to finish number one as well for the end of the year. For that it's going to take a great stretch again, winning Basel, Paris and London I assume to give myself a chance,” said the 17-time Grand Slam champion.

“We'll see how it goes. Look, I'm relaxed about it. I'll give everything I can. I want to get through this season well and finish strong.

“But it's not the number one goal right now. Right now it's to manage my schedule, hopefully be in good shape for Basel, then kind of go from there.

“Just to repeat, the goal was to become world number one this year, which happened, not the end of the year. But if that happens, that's a bonus.”

For a long time it appeared that Federer, overtaken by younger rivals Rafael Nadal and Djokovic, would never return to top spot – leaving him agonisingly short of Pete Sampras's record of total weeks at number one.

Used to regularly picking up Grand Slam wins, Federer, who has won six titles this year, went nine majors without a victory, fuelling speculation he was a fading force.

But his Wimbledon triumph this year – where he beat Murray in the final – catapulted him back to the top of the rankings. A week later he overtook Sampras's mark of 286 weeks.