The 2019 ATP Tour ended with Stefanos Tsitsipas defeating Austrian Dominic Thiem 6-7 (6), 6-2, 7-6 (4) in two hours and 35 minutes to lift his maiden ATP Finals title at the O2 Arena in London on Sunday.

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Tsitsipas became the first Greek player to win the prestigious trophy.

The final ATP rankings were released on Monday and we take a look at the biggest gains and declines of the year of the top 20 as well as the continued dominance of the Big Three.

BIGGEST GAINS

Matteo Berrettini (44 places): The current world No. 8 had a memorable 2019. Beginning the year ranked 52nd, He won two titles, in Stuttgart and Budapest, and finished runner-up in Munich. The 23-year-old was the last player to qualify for the ATP Finals and finished his season on a high when he beat Domininc Thiem in his last round-robin match to become the first Italian to win a match at the year-ender.

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MADRID, SPAIN - NOVEMBER 18: Matteo Berrettini of Italy celebrates a point against Denis Shapovalov of Canada during Day 1 of the 2019 Davis Cup at La Caja Magica on November 18, 2019 in Madrid, Spain. (Photo by Alex Pantling/Getty Images)

 

Stan Wawrinka (43 places): Currently the second-best Swiss on the tour, Stan Wawrinka's progress in 2019 was commendable. The three-time Gtand Slam champion, who dropped to world No. 263 in June 2018, began the year placed 59th and slipped further down to 68th in February. The 34-year-old  then saw a change in fortunes and fought his way back up to 16th. He hasn't won a singles title since 2017, but with consistent performances on the tour and finishing second best in Antwerp and Rotterdam, he managed to finish in the top 20.

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2019 US Open Tennis Tournament- Day Nine. Stan Wawrinka of Switzerland reacts during his match against Danill Medvedev of Russia in the Men's Singles Quarter-Finals match on Arthur Ashe Stadium during the 2019 US Open Tennis Tournament at the USTA Billie Jean King National Tennis Center on September 3rd, 2019 in Flushing, Queens, New York City. (Photo by Tim Clayton/Corbis via Getty Images)

 

Gael Monfils (22 places): The flamboyant Gael Monfils will always make his presence felt on the court with his showboating and his exceptional athelticism. However, the French player has often been criticised for not living up to expectations. But 2019 tells a different story and his top-10 finish bears testament to it. Even though he only won one trophy, he reached the quarterfinals of a tournament on 10 occasions.

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2019 US Open Tennis Tournament- Day Ten. Gael Monfils of France in action against Matteo Berrettini of Italy in the Men's Singles Quarter-Finals match on Arthur Ashe Stadium during the 2019 US Open Tennis Tournament at the USTA Billie Jean King National Tennis Center on September 4th, 2019 in Flushing, Queens, New York City. (Photo by Tim Clayton/Corbis via Getty Images)

 

 

ATP RANKINGS TABLE: [Top-20]

[ "+" shows gain | "-" shows drop | "~" shows no change]

 

Another Big year for Big Three

Novak Djokovic, Rafael Nadal and Roger Federer continue to rule the top of the ATP rankings.

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Nadal displaced Djokovic from the top spot on November 4, but the latter still had a shot of taking his position back at the ATP Finals. However, the Serb lost to Roger Federer and crashed out at the round-robin stage.

Nadal finished as world No. 1 for the fifth time, winning two Grand Slams (the French and US Opens) and two Masters 1000 titles (Rome and Rogers Cup) along the way.

ALSO READ | Federer says it's still 'easy to get motivated'

Novak Djokovic finished as the joint-most successful player in terms of titles won, tied with Thiem on five. The Australian Open and Wimbledon champion slipped to second just a day after winning the Paris Masters on November 3.

Roger Federer secured a top 3 finish for a third consecutive year and the 15th time overall. The Swiss Maestro clinched trophies in Basel, Halle, Dubai and Miami, and lost the Wimbledon final to Djokovic after holding match points in the fifth set. The 38-year-old is the only player who maintained his ranking throughout the year. Talk about class being permanent.

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NEW YORK, NY - AUGUST 23: Novak Djokovic of Serbia; Rafael Nadal of Spain and Roger Federer of Switzerland on stage during the ATP Heritage Celebration at The Waldorf=Astoria on August 23, 2013 in New York City. (Photo by Matthew Stockman/Getty Images)

 

BIGGEST DROPS

John Isner (9 places): The American ended the year with a win-loss record of 30-18 and a solitary title in Newport. His lack on consistency on the tour and an improved year for the likes of Alex de Minaur, Denis Shapovalov and David Goffin meant the 34-year-old slipped down the rankings from 10th to 19th.

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NEW YORK, NEW YORK - AUGUST 31: John Isner of the United States reacts during his Men's Singles third round match against Marin Cilic of Croatia on day six of the 2019 US Open at the USTA Billie Jean King National Tennis Center on August 31, 2019 in Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)

 

Karen Khachanov (6 places): The tall and lanky Russian, 6'6" to be precise, caught everyone by surprise with his gigantic forehand drives last year. The Russian's rapid success made him one the favourites to break past the Big Three in Grand Slams, but the 23-year-old flattered to deceive. With a win-loss record of 29-26, he failed to even reach a final the entire year.

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MONTREAL, QC - AUGUST 10: Look on Karen Khachanov (RUS) during the ATP Coupe Rogers semifinal match on August 10, 2019 at IGA Stadium in Montréal, QC (Photo by David Kirouac/Icon Sportswire via Getty Images)

 

 

[Data: ATP]