Roger Federer has opened up about being pipped at the post by Rafael Nadal in the race to end the year as World No.1.
Nadal secured his place in history on Wednesday when he beat Hyeon Chung at the Paris Masters, securing the year-end No.1 spot and becoming the oldest player ever to do so.
With Federer skipping the Paris Masters to be ready for the ATP Finals, Nadal only needed one victory to seal his place as year-end No.1, which he did with a 7-5 6-3 victory.
Federer has since revealed his disappointment about letting Nadal get away from him after both men enjoyed an incredible resurgence in 2017.
Federer says he regrets not being able to stop Nadal winning the US Open, where his was upset in the quarter-finals by Juan Martin del Potro.
“Ever since Rafa won the US Open, I knew it was going to be very, very difficult,” Federer told The Wall Street Journal.
“I wish I could have chased [No. 1] more — my only regret is that I couldn’t have chased it more at Cincinnati and the US Open.
“That was a pity — but Rafa played a full schedule, and he deserves it. I’m OK with that.”
While Nadal has played as many tournaments as possible in 2017, Federer has rested whenever he could and skipped the entire clay-court season, where Nadal won three titles, including the French Open.
But Federer admits he was “scared” of getting injured, the reason he decided to skip Paris.
“Do not believe that the place of No.1 does not interest me anymore,” he told Swiss newspaper 20 Minuten.
“In the end, that's why we play tennis.
“And missing this tournament Bercy that I love, which is played in a city that I love too, costs me a lot.
“But I'm too scared to hurt myself."
Nadal had not finished the year at the top since 2013, with Novak Djokovic and Andy Murray doing so after that.
"One year ago, for sure I never dreamed about being No.1 again at the end of the season," Nadal said.
Nadal's comeback from injury, loss of form and confidence, has been remarkable.
He reached three grand slam finals this year, losing to Roger Federer at the Australian Open and winning a 10th French Open title before clinching the US Open for the third time.
"It was impossible for me to think about (being No.1) coming back from a tough period without playing, and with so many injuries in the last couple of years," he said.
"It means a lot. After almost 10 years since the first time."
The only downside to his remarkable season has been always losing to Federer, who leads the ATP Tour with seven titles this year.
Federer has beaten Nadal four consecutive times - not dropping a set in three of them - and the 19-time grand slam champion was in outside contention for the No.1 ranking before pulling out of Paris.