Beijing: Rafael Nadal will return to number one in the world rankings after his semi-final opponent Tomas Berdych retired injured at the China Open Saturday, capping an astonishing comeback for the 13-time Grand Slam champion.
The Spanish world number two only needed to make the final in Beijing to edge ahead of Novak Djokovic in the new rankings, which will be announced by the ATP on Monday.
Nadal, who last topped the rankings in July 2011, has enjoyed a remarkable season, returning from injury to dominate the hardcourt tournaments.
Nadal will overtake defending China Open champion Djokovic at the top of the rankings even if the Serb overcomes France's Richard Gasquet in his semi-final later Saturday and retains the title on Sunday.
Djokovic is currently on his 101st week as the top ranked player.
Czech Berdych pulled out of his semi-final after receiving treatment for an injury with Nadal leading 4-2 in the first set.
Nadal had broke Berdych's serve in the fifth game after the pair appeared to be matching each other competitively in the early stages.
The world number five told reporters after the match that he suffered a back injury when he reached for a shot.
He then praised Nadal's achievement on reclaiming the top spot.
"With Rafa, well, just all the credit. It is really incredibly well done in the whole short time that he has become a number one again," he said.
"That's really an achievement for an athlete like him."
Nadal, sidelined for the second half of last year with a knee injury, has finished the season as number one twice before, in 2008 and 2010, and is unbeaten since he crashed out of Wimbledon in the first round in June.
The 27-year-old, tipped to eclipse Roger Federer's record of 17 Grand Slam titles, has won 10 ATP World Tour titles in 2013.
Tennis legends Andre Agassi and Pete Sampras reportedly said Nadal could overtake Federer before he finishes his career.
But Nadal remained philosophical on what would be another major achievement when asked about the goal earlier this week in Beijing.
"If that happens or that not happens, the only thing I am sure is when I am going to leave this tour, I am going to be very happy about what I did," Nadal told reporters.
Nadal believes he would need to sustain his form -- and crucially his fitness -- for the next four years if he is to better Federer's Grand Slam achievements.
The current game is said by tennis pundits to be dominated by the 'Big Four' -- Nadal, Federer, Djokovic and Briton Andy Murray.
However, Nadal is emerging as the dominant force and he has had the beating of Djokovic, coming out on top at both the French Open and US Open, as well as the Canada Masters.
Djokovic has previously warned Nadal that he won't give up the top spot without a fight.
"As long as there is a chance, I will fight for that top spot," he said ahead of the dual ATP and WTA event, which is being staged at Beijing's Olympic Park.