Novak Djokovic has said he is never short on self-belief but his return to the top of the men's singles rankings after being ranked as low as 22 in June seemed "highly improbable" to even himself.
The Serb officially replaced Rafael Nadal as the numero uno of tennis on Monday, November 5, marking his return to the top of the charts after nearly a two-year absence.
Djokovic, who will be enjoying the 224th week at number one, has become the first player since Marat Safin in 2000 to be ranked outside the top 20 and then climb to the top spot in the same season.
Safin was ranked 38 in February 2000 and reached the top spot in November 2000, according to ATP's official website.
"Reflecting on what I've been through in the last year, it's quite a phenomenal achievement. And, of course, I'm very, very happy and proud about it. Five months ago, if you told me that, I would be — I always believe in myself, but it was highly improbable at that time considering my ranking and the way I played and felt on the court," Djokovic said.
"I will probably be able to speak more profoundly about it when the season is done and hopefully if I get to finish as No. 1."
The newly-crowned numero uno was seemingly dejected and hopeless after the early-season hard court swing. Djokovic had undergone a small medical intervention on his elbow in order to fix a long-standing injury but a rushed comeback hampered his progress.
Nonetheless, Djokovic rallied against the odds and stunned a strong field at Wimbledon, after which he has won three titles, including the US Open.
Djokovic was stunned in the Paris Masters final on Sunday by 22-year-old Karen Khachanov in straight sets but the 31-year-old had already done enough to seal the top spot.
Djokovic heaped praise on Khachanov, who won his first Masters 1000 title while expressing satisfaction with the way the last few months have panned out for him.
"I'm satisfied of course and I'm going to be No. 1 tomorrow officially. What more can I ask for? I mean, I won 20-plus matches in a row and had a most amazing last five months of the year," Djokovic added.
Djokovic will now be hoping to retain the top spot and finish the year as the number one as he is slated to play the season-ending ATP World Tour Finals, starting November 11 in London.
It will be a two-way battle between Djokovic and Nadal as the Serb has only a 565-point lead over the southpaw, going into the premier season-ending tournament.