Novak Djokovic receives his stamps at the PTT Museum in Serbia.

Novak Djokovic will face Alexander Zverev in the semi-finals on Saturday at the Nitto ATP Finals.

Novak Djokovic defeats Cameron Norrie on Friday in Turin.

Novak Djokovic records his 50th match win of the season on Wednesday to qualify for the semi-finals at the Nitto ATP Finals.

Novak Djokovic lifts the 2021 year-end ATP Tour No. 1 trophy presented by FedEx on Monday in Turin.

Novak Djokovic defeats Casper Ruud on Monday in Turin.

Andrey Rublev, Alexander Zverev, Matteo Berrettini, Novak Djokovic, Daniil Medvedev, Stefanos Tsitsipas, Casper Ruud and Hubert Hurkacz walk towards the Piazza San Carlo in Turin

Daniil Medvedev believes Novak Djokovic's achievements of the past 12 months are earning him more respect.

Novak Djokovic and Daniil Medvedev pose for photos ahead of their 10th ATP Head2Head meeting in the Paris final.

Novak Djokovic defeats Hubert Hurkacz in three sets on Saturday to advance to the Paris-Bercy final.

Five-time former champion Novak Djokovic beats Taylor Fritz on Friday for a place in the Paris semi-finals.

Novak Djokovic defeats Marton Fucsovics on Tuesday in Paris in his first singles match since the US Open final.

Novak Djokovic will play Fabio Fognini or Marton Fucsovics in his Paris opener.

Novak Djokovic slides to hit a backhand during the US Open final on Sunday.

Novak Djokovic fires a backhand during the US Open final on Sunday.

Novak Djokovic and Daniil Medvedev hug after the Russian defeats the World No. 1 to win his first major title at the US Open.

Daniil Medvedev and Novak Djokovic embrace at the net ahead of the US Open final.

Novak Djokovic falls to Daniil Medvedev in the US Open final in his only Grand Slam defeat of 2021.

Novak Djokovic celebrates a five-set win against Alexander Zverev on Friday evening in the US Open semi-finals.

Novak Djokovic improves to an unbeaten 12-0 in US Open quarter-finals after defeating Matteo Berrettini on Wednesday night.

Novak Djokovic recovers from a set down to defeat American Jenson Brooksby and set a US Open quarter-final clash with Matteo Berrettini.

Novak Djokovic has dropped the first set eight times in 25 Grand Slam matches this year... and rallied to win them all.

Novak Djokovic takes on American wild card Jenson Brooksby for the first time in the fourth round of the US Open on Monday night.

Top seed Novak Djokovic now leads Kei Nishikori 18-2 in their ATP Head2Head Series.

Novak Djokovic defeats Holger Vitus Nodskov Rune in four sets on Tuesday evening to reach the second round of the US Open.