(CNN) -- Rafael Nadal has been No. 1 in the world rankings before. In two stints, in fact.
But it's safe to say getting to top spot for a third time is a little extra special for the Spaniard.
When Nadal reached the final of the China Open in Beijing, he was guaranteed of overtaking Novak Djokovic when the rankings are released Monday. The exclamation point for Nadal would be beating the defending champion in Sunday's title match.
"(This is) a great year, one of the best years of my career without any doubt," Nadal said on the ATP Tour's official website after Saturday's semifinal opponent Tomas Berdych retired due to a back injury at 4-2 down in the opening set.
"It sure is special be back to the top position of the rankings after more than a half year without playing tennis. I worked hard every day with the right attitude I think, and because of that, I am today in this situation. I am number one today, but it's not (assured) for the end of the season."
Not many, including Nadal, could have seen this coming.
Last year, he suffered a shock second-round loss at Wimbledon and went on to miss seven months with a knee injury.
There were whispers that he might never return to the tennis tour.
He did, however, come back and since then has been almost unstoppable, capturing two majors in 2013 to lift his tally to 13 -- a mere four behind men's record-holder Roger Federer.
"I won't go to sleep tonight feeling that I am the best player of the world. That's something that I never thought, and I don't think that now today," said Nadal. "I played a very complete season, and that's why I am the best in the rankings today."
The 27-year-old's record stands at a dazzling 65-3, meaning he's on course to put together one of the finest seasons ever in terms of winning percentage.
Nadal suffered a first-round loss at Wimbledon this year to Steve Darcis amid speculation his famous knees were bothering him again.
With his form uncertain heading into the US Open Series, though, Nadal captured the Canadian Masters in Montreal and Cincinnati Masters before finishing his North American road trip with an emphatic win at the U.S. Open.
There he downed Djokovic.
Whereas the Australian Open champion once owned a seven-match winning streak against Nadal, he has now lost six of their last seven tussles.
"I know tomorrow I going to have a very tough opponent," Nadal said. "I need to play my best, playing aggressive, playing without mistakes, being solid with my serve. If these kind of things are not happening, I will not have chances.
"I know what I have to do but it's very difficult to do it, because the level of the opponent is unbelievable."
The Serbian reached the China final for the fourth time in five years after beating French fifth seed Richard Gasquet 6-4 6-2 in Saturday's second semifinal, and will be seeking to add to his titles from 2009, 2010 and last year.
Nadal won the tournament back in 2005, the year after it was reinstated to the ATP Tour calendar.
The only major tournament Nadal hasn't won -- apart from his majors, he possesses an Olympic gold in singles and has won multiple Davis Cups -- is the ATP's year-end championships.
But he'll likely be the favorite for the November event in London.
Although Djokovic relinquished his No. 1 ranking -- he has held it for 101 non-consecutive weeks -- he will lead Serbia when it faces the Czech Republic in the following Davis Cup final.
Meanwhile, world No. 1 Serena Williams will face Serbia's Jelena Jankovic in the final of the women's event in Beijing.
Williams crushed Polish third seed Agnieszka Radwanska 6-2 6-2 on Saturday, while Jankovic defeated last weekend's Tokyo winner Petra Kvitova 6-7 (7-9) 6-1 6-1.
Williams is seeking to add to her 2004 China triumph, with the American aiming to win her 10th title this year -- the best on the WTA Tour since Justine Henin managed the same number in 2007.
Former world No. 1 Jankovic, seeded eighth this week, won the Beijing title in 2008 and was runner-up the previous year.
She is one of only two active players to have beaten Serena four times or more -- the older Williams sister Venus is the other.
"She's the best player in the world right now," Jankovic said of the U.S. Open champion. "She's in unbelievable form. Even though I have beaten her in the past I think she's the most difficult player to play against."