It was Andy Murray's second victory over a top-10 opponent in the past two weeks. He will next face Tommy Paul.
Andy Murray saved a set point before closing it out on his third match point in the Stockholm Open.
The victory marks Marin Cilic's fourth title in Russia after two wins in 2014 and 2015 in Moscow.
This is the first loss for British tennis player Andy Murray in 10 matches at the Austrian indoor event.
The 34-year-old 3-time Grand Slam Champion will face Casper Rudd of Norway in the round of 16.
The contest stretched to almost five hours and Murray didn't appreciate Tsitsipas taking a medical timeout after the third set and a lengthy visit to the locker room after the fourth
Murray lost to much younger Tsitsipas 2-6, 7-6 (7), 3-6, 6-3, 6-4, as the year's last Grand Slam tournament got underway
Murray now heads to the US Open, where he won the first of his three Grand Slam titles in 2012
Murray's ranking slid out of the top 100 after he had two hip operations in recent years
Andy Murray remained in the doubles tournament with partner Joe Salisbury. Murray and Salisbury beat the second-seeded French team of Pierre-Hughes Herbert and Nicolas Mahut 6-3, 6-2 on Saturday
Denis Shapovalov defeated Andy Murray,a two-time champion at Wimbledon, 6-4, 6-2, 6-2,
After wasting a pair of match points and ceding the third set, Murray defeated Basilashvili 6-4, 6-3, 5-7, 6-3
Andy Murray is making a return, while Coco Gauff hopes to make an impression again even as Wimbledon rings in a host of changes
A five-time champion of this event, Murray was a wild-card entry. He will play at Wimbledon in less than two weeks as a wild card.
The Gentlemen's and Ladies' singles winners at Wimbledon will each get USD 2.4 million, a nearly 28 percent decrease from the 2019 edition
Andy Murray will miss the French Open as he focuses on being ready for playing on grass at Queen's Club and Wimbledon
Former world number one Andy Murray will compete at the Miami Open for the first time since 2016 after being granted a wildcard.
Robin Haase took the first set in Rotterdam, but Andy Murray bounced back to seal his place in the second round
New elected German Chancellor Olaf Scholz holds his letter of appointment presented by German President Frank-Walter Steinmeier during a reception at Bellevue Palace in Berlin, Germany. Scholz has become Germany's ninth...AP Photo/Michael Sohn
New elected German Chancellor Olaf Scholz (not in the picture) has given flowers to former Chancellor Angela Merkel during a handover ceremony in the chancellery in Berlin. Merkel was the German Chancellor for 16 years....Photo/Markus Schreiber
A surfer enters the Mediterranean Sea during stormy weather in Tel Aviv, Israel.AP Photo/Oded Balilty
A U.S. Coast Guard diver, tethered to a hovering helicopter, pulls a body from a submerged vehicle stuck in rushing rapids just yards from the brink of Niagara Falls in Niagara Falls, New York.AP Photo/ Jeffrey T. Barnes
Corinthians' Gabi Zanotti celebrates after scoring against Sao Paulo during a Sao Paulo championship Women's soccer final match at Neo Quimica arena in Sao Paulo, Brazil.AP Photo/Andre Penner
Young, brash and little-known artistes are using hip-hop as an outlet to speak up and speak out.
Aamir Shaikh aka Shaikhspeare traces talks about the genre that uses music as a means to dissent.
Family from UP village forced to run around to complete post-death official paperwork and even last rites.
On BR Ambedkar's death anniversary, a look at the 'invisible' history of Dalit Bahujan women in Indian politics.
While everyone is going gaga over actress Katrina Kaif in the revamped version of 'Tip Tip Barsa Pani', the replacement of Raveena Tandon does point towards the problem of sexism and ageism in the Indian film industry
Australia winning the T20 World Cup for the first time has been timely as they host the next edition at their own backyard in 2022.
As per the Observer Research Foundation, close to 250 million children in India were adversely affected due to school closures due to the early lockdowns imposed by the government in response to Covid-19.