It was Rafael Nadal who convinced Andy Murray to train in Spain, a decision that changed the path of his career.

Now the Spaniard has improved Murray's chances of qualifying for the ATP World Tour Finals in London.

Nadal announced last night that he will not be playing at next week's Paris Masters or in London because he needs surgery on his appendix, opening up an extra spot for the season-ending event.

That could benefit Murray, who yesterday reached the semi-finals of the Valencia Open 500 by beating South Africa's Kevin Anderson 6-7 (3-7), 6-4, 6-4.

With the top eight qualifying for London - or the top seven plus US Open champion Marin Cilic if he finishes outside the top eight - Murray stands eighth.

But the Scot, who faces David Ferrer today for the third time in three tournaments, now has a little extra space to breathe as he tries to qualify for the event for the seventh straight year.

Novak Djokovic, Roger Federer, Stan Wawrinka and Cilic are the only men to have officially clinched their spots but Murray could go fifth in the Race to London if he wins the title in Valencia.

To do that, the 27-year-old must get past Ferrer, whom he beat in the Vienna final last weekend but whom he lost to in Shanghai the previous week.

With Ferrer right behind him in the Race, Murray knows the importance of their semi-final clash, a realisation that was clear from his win over Anderson.

Judging Murray's state of mind during matches is usually a thankless task but when he flicked a backhand pass to break serve late in the second set, his intent was clear.

From that moment on, having broken for 5-4 and then served out the set to level their quarter-final match in Valencia, Murray was in control.

His London hopes were also assisted by the defeat of Milos Raonic, who began the week in ninth place, by David Goffin in the quarter-finals of the Swiss Indoors in Basel.

Murray made it 16 wins out of 18 by beating Anderson but he found himself a break down early on as the South African's big serve caused him problems.

After getting back on terms and forcing the tiebreak, Murray dropped the opening set and his body language was hinting at an early trip home.

But the turning point came when he chased down a drop volley to lift a backhand pass for a winner when holding break point at 4-4.

The double fist-pump showed how much it meant and after serving out for the set, Murray broke in the opening game of the decider and held his advantage throughout to clinch a hard-earned victory.

Ferrer clinched his 600th win on the ATP Tour yesterday when he took care of Brazilian Thomaz Bellucci 6-1, 6-2 to take his place in the last four.

In Basel, Roger Federer gave Murray and Ferrer an additional boost when he beat 11th-placed Grigor Dimitrov 7-6, 6-2, denting the Bulgarian's qualification chances.

Nadal's title hopes were ended by Serbian teenager Borna Coric, who earned the biggest win of his career with a 6-2, 7-6 (7-4) victory.

Coric will play Goffin in the semi-finals today while the other semi-final will be between Roger Federer and Ivo Karlovic.