The top eight men in the world descended on London's O2 Arena this week for the Nitto ATP Finals. The players were split into two groups of four, with the top two players from each round-robin pool advancing to an elimination bracket to determine the year-end champion.
Three former champions are in the field—Alexander Zverev, Roger Federer and Novak Djokovic—and Federer, Djokovic and Rafael Nadal are the Top 3 seeds at the event for the fourth time.
Let's take a look at the players competing this week in London.
Dominic Thiem reached the final of the French Open for the second year in a row in 2019, but he was unable to back up his 2018 quarterfinal run at the US Open, falling in the first round. He advanced to the semifinals of the Nitto ATP Finals this week in London.
Roger Federer has won the ATP Finals six times, the most recent of which came in 2011. The five-time US Open champion split his first two round-robin matches, then knocked out Novak Djokovic with a 6-4, 6-3 win on Thursday in the English capital.
Daniil Medvedev had a breakout year in 2019, reaching the final of the US Open and climbing to No. 4 in the world. He won more matches than any other player on tour and was named the US Open Series Breakout Player after reaching consecutive finals at the Rogers Cup and Western & Southern Open. The Russian lost his opening two matches, including against Rafa Nadal in a match he led 5-1 in the final set, but can still qualify if he beats Alexander Zverev on Friday and other results go in his favor.
Matteo Berrettini climbed inside the Top 10 for the first time in his career this fall, reaching No. 8 on Nov. 4. The 6-foot-5 Italian lost to Roger Federer and Novak Djokovic in pool play, eliminating him from contention for a semifinal spot.
Rafael Nadal finished runner-up at the ATP Finals in 2010 and 2013, but a remarkable comeback in his second round-robin match against Daniil Medvedev might be just what he needs to finish the year on a high. The reigning US Open champion rallied from 5-1 down in the decider to beat Medvedev in a rematch of September's finale in New York City. The Spaniard plays Stefanos Tsitsipas in his third and final pool match Friday.
Three-time US Open champion Novak Djokovic was aiming to win his fifth year-end ATP Finals title, following successes in 2008, 2012, 2013, 2014 and 2015. Djokovic defeated Mario Berrettini but lost to Dominic Thiem, and then fell to Roger Federer in a final group stage matchup Thursday to end his 2019 season.
Stefanos Tsitsipas won his first two matches in London, defeating Daniil Medvedev and Alexander Zverev. The 21-year-old Greek, the youngest player in the year-end tournament, is assured of a spot in the semifinals, regardless of what happens in his final round-robin match with Rafael Nadal.
Defending ATP Finals champion Alexander Zverev upset world No. 1 Rafael Nadal in his opening match before winning just five games against red-hot Stefanos Tsitsipas, who is still yet to drop a set at the O2 Arena. Zverev, who reached the fourth round of the US Open this summer, rounds out pool play against Daniil Medvedev on Friday.
