He also overtook his career-best 65-season win tally of 2023 with this win.
Dimitrov has enjoyed the best season of his career in 2017, clinching four titles overall, including his first Masters title in Cincinnati.
Rafael Nadal's decision to end his season early means Cilic is actually holding the last berth for the eight-man showdown at London's O2 Arena.
World tennis No 4 Rafael Nadal has pulled out of the Paris Masters and the ATP World Tour finals in London as he is still recovering from his left knee injury, the ATP said on Thursday.
Roger Federer chalked up yet another record when victory over Janko Tipsarevic at the ATP World Tour Finals on Tuesday put him top of the list for match wins at the traditional season-ender. The 17-times Grand Slam champion cruised to a 6-3, 6-1 victory over the Serbian world number nine, taking his haul of victims in the event to 40, one more than Ivan Lendl.
Greece's Tsitsipas battled back from 3-5 down in the third set to eliminate Medvedev with a 6-3, 6-7(11), 7-6(1) win to set up a showdown on Friday with Rublev for the Red Group's other semi-final spot.
Russian sixth seed Anastasia Pavlyuchenkova claimed her third title of the year by beating seventh-seeded Australian Daria Gavrilova in the final of the Hong Kong Tennis Open on Sunday.
Six-time champion Novak Djokovic has withdrawn from this year's Italian Open, organisers said on Tuesday.
Mahesh Bhupathi and Rohan Bopanna won their first match at the ATP World Tour Finals, scoring a 6-3, 5-7, 10-5 victory over Robert Lindstedt and Horia Tecau in Group B to keep their semi-final hopes alive, while Leander Paes and Radek Stepanek also made a winning start.
France's Boisson wins first WTA title in Hamburg
With 1,500 points available for an undefeated champion next week, the tournament could produce a thrilling climax with Murray and Djokovic, who have never met at the O2, facing off in the final for the year-end number one ranking.
"It has been an amazing year. One year ago, for sure I never dreamed about being World No. 1 again at the end of the season. It's something that means a lot to me. But the season is not over."
Nikolay Davydenko sealed the last semi-final berth at the ATP World Tour Finals on Friday, claiming the victory he needed over Robin Soderling, to send 2008 champion Novak Djokovic spinning out of the tournament.
Maria Sharapova was officially inducted into the International Tennis Hall of Fame on Saturday night in Newport
Novak Djokovic moved to the brink of his 100th tour-level title after recovering from a second-set blip to beat British qualifier Cameron Norrie 6-4, 6-7(6), 6-1 in the Geneva Open semi-finals on Friday.
Mahesh Bhupathi and Rohan Bopanna sealed a place in the semi-finals at the ATP World Tour Finals after getting the better of the second-ranked Belarusian-Canadian pair of Max Mirnyi and Daniel Nestor at the O2 Arena in London on Friday. In a tense Group B match that could have gone either way, the world No 5 Indian duo prevailed 7-6(5), 6-7(5), 10-5 in an hour and 55 minutes.
World No 8 Switzerland's Stanislas Wawrinka confirmed, on Monday, his participation in the 19th edition of the Aircel Chennai Open, India's only ATP World Tour tennis event, starting December 30.
Australian bad boy Bernard Tomic has shrugged off his Miami arrest and banishment from the Davis Cup team to successfully defend his ATP title in Bogota.
But the big question that keeps striking the mind is, if Indian tennis system can actually claim this win as its own. The answer is: partially.
Paire, ranked 29 in the world, said the sport had become a 'tasteless job'.
The tournament's once-robust pool of around 300 line judges has been cut to 80 and they will serve as "match assistants", who support chair umpires and step in should the ELC -- powered by more than 450 cameras -- fail in any of the 18 courts in use.
Novak Djokovic fought back from a set down to beat Andy Murray 4-6, 6-3, 7-5 at the ATP World Tour Finals on Wednesday and all but seal a place in the last four of the season-ending tournament.
The message from Novak Djokovic could not have been more emphatic after the Serb retained his title at the ATP World Tour Finals with a crushing victory over Rafa Nadal on Monday.
Roger Federer and Andy Murray avoided the need for fiddly mathematics on Thursday as they both produced dominant displays to qualify for the semi-finals of the ATP World Tour Finals.
The hardest nut in men's tennis again proved resistant to the heaviest of sledgehammers as Novak Djokovic absorbed the brute force of Juan Martin del Potro to book his place in the last four of the ATP World Tour Finals on Thursday.
Grigor Dimitrov claimed the biggest title of his career and sent out a huge statement of intent as the stylish Bulgarian beat David Goffin 7-5, 4-6, 6-3 to win the ATP Finals.
Novak Djokovic battled from a set down to clinch his 100th tour-level title by beating Polish sixth seed Hubert Hurkacz 5-7, 7-6(2), 7-6(2) at the Geneva Open on Saturday.
Argentina's Juan Martin del Potro found himself in a strangely familiar position at the ATP World Tour Finals on Thursday after keeping his hopes on track with victory over Janko Tipsarevic.
Indian ace Leander Paes and his partner Lukas Dlouhy suffered a straight-set defeat against American Byran brothers Bob and Mike to be out of contention for a semi-final spot in the ATP World Tour Finals in London.
Zverev and Shelton tested each other in a high-quality encounter before the world number three played a near flawless tiebreak to clinch the match in little over two hours and stretch his career win-loss record over the American to 3-0.
Jannik and Carlos are the favourites at Flushing Meadows, but don't write these men off!
The fast rising Indian pair of Divij Sharan and Purav Raja clinched its first ever ATP tour level title with a hard-fought win over Edouard Roger-Vasselin and Igor Sijsling in the summit clash of the Claro Open, in Bogota.
Top seed and defending champion Jannik Sinner, playing on his 24th birthday, ended French qualifier Terence Atmane's dream run at the Cincinnati Open with a 7-6(4), 6-2 win on Saturday to reach the final of the US Open tune-up event.
Japan's Kei Nishikori will make a third straight appearance at the ATP Tour finals next month after becoming the fifth player to qualify for the season-ending tournament, organisers said on Wednesday.
Switzerland's challenge at the ATP World Tour Finals melted away like an Alpine glacier in a heatwave on Sunday as Rafa Nadal and Novak Djokovic marched on to the grand finale.
Carlos Alcaraz heads to the US Open in his now-familiar role as chief challenger to defending champion Jannik Sinner and the Spaniard will be driven this year by the twin pursuit of Grand Slam glory and the World No. 1 ranking.
Six-time champion Roger Federer survived a late-night Swiss semi-final thriller against Stanislas Wawrinka on Saturday to set up an ATP World Tour Finals showdown against Novak Djokovic.
Roberto Bautista Agut, the world No. 15, has confirmed his participation in the 20th edition of the Aircel Chennai Open, to be held at SDAT Stadium in Nungambakkam from January 5 to 11 next year.
Speculation is rife that all is not well in among compatriots Roger Federer and Stanislas Wawrinka.
Rafael Nadal says he could miss the season-ending ATP World Tour Finals next month because of appendicitis.
