LONDON (AFP) - Rafael Nadal believes his return to the top of the world rankings after a seven-month injury nightmare is one of the greatest achievements of his remarkable career.
Just 12 months ago, Nadal was sitting at home in Manacor watching the ATP World Tour Finals on television as he contemplated the depressing thought that he may never again get the chance to compete for the sport's top prizes.
At the time the Spaniard was in the midst of a draining battle to recover from a severe bout of the knee tendinitis which has plagued him for years and, with no cure in sight, he was starting to fear the worst.
But fast forward one year and Nadal's present and future suddenly look a whole lot brighter.
The 27-year-old eventually found a solution to ease his knee pain and, after returning to the Tour in February, he quickly made up for lost time.
Nadal, who was fifth in the world when his comeback started, won the French and US Open titles, as well as eight tournaments, and in the process reclaimed top spot from Novak Djokovic - a supremely dominant run which reached a new peak at the Tour Finals in London on Wednesday.
He arrived in England knowing two wins in Group A of the round-robin event would ensure he finished 2013 top of the world and he did just that, defeating Swiss seventh seed Stanislas Wawrinka 7-6 (7/5), 7-6 (8/6) after beating David Ferrer 24 hours earlier.
Nadal's majestic career has featured many highs, among them eight French Open crowns and two Wimbledon titles, including a breathtaking five-set win over Roger Federer in the 2008 final, but even he felt little could surpass this glorious comeback.
"During all this season I said finishing top of the rankings was not my goal, but the truth is after all the success I had during the season, I think that after all what happened last year, I felt I deserved to be there at the end of the season. And today I did it," Nadal said.
"It was one of the best things that I did in my career, to come back to the number one after three seasons.
"That's very difficult in our sport, and after a very important injury.
That's an emotional thing for me."