The German is the first lucky loser to reach the final of a Masters 1000 event.
Fifth seeds Rohan Bopanna and Edouard Roger-Vasselin booked a quarter-final berth in the ATP Paris Masters but Leander Paes and Daniel Nestor were ousted after a straight sets defeat, in Paris.
Novak Djokovic cruised past Germany's Jan-Lennard Struff 6-3, 6-1 on Wednesday to reach a record-equalling eighth Western & Southern Open semi-final in New York where he will face Spaniard Roberto Bautista Agut.
For the first time since 2004, neither Novak Djokovic nor the injured Rafael Nadal will be in the Rome final.
Tsitsipas regained his composure to save a set point in the 10th game before sealing the victory in the tiebreak for his third career title.
Roger Federer has now won all the seven finals he has contested in Cincinnati. Rediff.com takes a look at a few other events that have ensured prolific returns for the Swiss master.
'I'm disappointed and sad because after a good start to the season I was coming to a very important part of the year with very good feelings and good results.'
World No 2 Novak Djokovic produced a magical display to overcome the ferocious hitting of Argentine Juan Martin del Potro and successfully defend the Shanghai Masters title on Sunday.
Dhruv Munjal on why Novak Djokovic may yet win that highly contested title.
Rafael Nadal may have won the French Open a record 12 times but the Spaniard feels this year's conditions will be the most difficult he has ever faced at Roland Garros and mean he must be at his best to have a chance of retaining his title again.
World No. 2 Carlos Alcaraz defeated Tsitsipas in the 2021 US Open and in last year's Miami Masters and Barcelona Open.
Top seed Novak Djokovic made quick work of Tennys Sandgren at the Western and Southern Open on Tuesday, never dropping serve en route to a 6-2, 6-4 win over the American, while big-serving Milos Raonic enjoyed a straight sets win over Andy Murray.
Summary of sports events and persons who made news on Thursday
World No 1 Novak Djokovic will meet second-ranked Andy Murray in a blockbuster final at the Madrid Open after beating Kei Nishikori 6-3, 7-6 (4) on Saturday.
India's number one singles player Prajnesh Gunneswaran beat Jay Clarke of Great Britain in straight sets to enter the main draw of the Miami Open, on Wednesday.
Raducanu retires in Rome as back injury persists, Jabeur survives early scare
Serbia have been drawn in Group B alongside Spain, South Korea and Canada.
World number one Novak Djokovic's French Open preparations were dealt with a blow as he suffered a 6-3, 4-6, 6-2 defeat by Russian Daniil Medvedev in the Monte Carlo Masters quarter-finals on Friday.
US Open champion Carlos Alcaraz has become the youngest world number one since the ATP rankings began in 1973.
A long season took its toll on Roger Federer on Thursday as the Swiss was knocked out of the Paris Masters following a 7-6(3) 3-6 7-6(5) third-round defeat by big serving John Isner.
Frenchman Jo-Wilfried Tsonga recorded a first win over Rafael Nadal in almost four years after producing some scintillating tennis to beat the Spaniard in the semi-finals of the Shanghai Masters on Saturday. He will face Novak Djokovic in the final.
Indian qualifier Prajnesh Gunneswaran achieved the biggest win of his career when he stunningly knocked out World No 18 Nikoloz Basilashvili at the Indian Wells ATP Masters event, continuing his dream run.
As the new World No 1, Andy Murray could be troubled by the weight of expectations on his shoulders at the ATP World Tour Finals, but the Briton just wants to enjoy his new status.
Spaniard David Ferrer produced one of his finest performances to edge world number one and compatriot Rafael Nadal 6-3, 7-5 in the Paris Masters semi-final on Saturday and keep alive his hope of retaining his crown.
Carlos Alcaraz announced himself in Madrid when he played with a sore ankle but still dispatched three top five players -- Rafael Nadal, Djokovic and Alexander Zverev -- en route to his second Masters title, just days after his 19th birthday.
WTA chief promises 'strong reactions' to ban on Russian, Belarusian players
Serbian former world number one Novak Djokovic will be in action at his home club, working under old coach Marian Vajda -- desperately searching for some spark after tumbling down to 13th in the rankings.
World number one Carlos Alcaraz will not play in the Australian Open after picking up a right leg muscle injury during pre-season training, the Spaniard said on Friday.
'There is so much excitement brewing about Wednesday's Alcaraz and Rune quarter-finals showdown -- it could well be a juicy foretaste of things to come.'
American teenage sensation Coco Gauff became the youngest player to win a WTA title in 15 years as she beat former French Open champion Jelena Ostapenko in the Linz Open final on Sunday.
Former world number one Roger Federer looked like his old self when he beat Argentine Juan Martin Del Potro 6-3, 4-6, 6-3 at the Paris Masters on Friday to set up a semi-final clash with Novak Djokovic. Top seed Rafa Nadal destroyed local favourite Richard Gasquet 6-4, 6-1 as he stepped up his bid for a record sixth Masters Series crown in the same season.
Petra Kvitova overcame a sluggish start and 10 double faults to beat Madison Keys 6-7(6), 6-4, 6-3 on Saturday and advance to the final of the Cincinnati Open, where she will face Caroline Garcia, the first qualifier to reach the final of a WTA 1000 tournament.
Top seed Novak Djokovic beat Canadian Felix Auger-Aliassime 7-5, 7-6(1) to reach the semi-finals of the Italian Open on Friday and move within one win of 1,000 career victories.
The French Open will be held in Paris from May 22 to June 5.
Men's governing body ATP on Monday unveiled a revised system for calculating world rankings when the season resumes in August following a five-month suspension due to the COVID-19 pandemic. Traditionally the ATP rankings operates on a formula of 18 best results over 52 weeks but will now cover a 22-month period from March 2019 through December 2020.
John Isner delved deep into his energy tank to outlast Germany's Alexander Zverev 6-7(4), 6-4, 6-4 and claim the biggest title of his career at the Miami Open.
Nadal committed 30 unforced errors to Schwartzman's 17 and had his serve broken five times.
The unseeded Indo-Canadian pair defeated their fancied rivals 6-3, 3-6, 10-5 in a round of 16 tie of the ATP Masters 1000 event.
Andy Murray is within one match of securing his place in the ATP World Tour Finals after easing past local favourite Julien Benneteau 6-3, 6-4 on Wednesday to advance to the third round of the Paris Masters.
Simona Halep ended Beatriz Haddad Maia's dream run in Toronto