US Open: Tsitsipas wins marathon five-setter against Murray

The Greek, who has now notched a tour-leading 49 victories this year, saved two set points at 4/6 in the second-set tie-break to avoid going down two sets to love, before advancing in a marathon four-hours-and-48-minute contest. 

"It is not easy," Tsitsipas said after the match. "I had to make lots of sacrifices to come back. I think the atmosphere was great today, with a lot of positive tennis. The New York crowd is known to be one of the best crowds in the world. The fact we are able to compete out here with an electric crowd today is something we have been waiting for," the Greek player was quoted as saying by atptour.com. 

Tsitsipas has enjoyed a strong North American hard-court swing, reaching the semifinals in Toronto and Cincinnati this month. 

Earlier this year, the 23-year-old reached the semifinals at the Australian Open and the French Open final where he lost to Serbian Novak Djokovic. However, the seven-time tour-level titlist has never advanced past the third round in three previous main draw appearances in New York. 

The Monte-Carlo champion, who was facing Murray for the first time on Monday, will next face Adrian Mannarino in the second round after the Frenchman defeated countryman Pierre-Hugues Herbert 3-6, 4-6, 6-4, 6-3, 6-3. 

"I hope I am able to keep my game at the same level [against Mannarino] as I managed today," Tsitsipas added. "Hopefully I will be back here on this court." 

In a high-quality first set, Murray looked to hit the ball down the line on his backhand as he dictated play with his aggressive groundstrokes to keep the Athens native pinned behind the baseline. He gained a double break to lead 4-1 and moved ahead when Tsitsipas cut a backhand return into the bottom of the net. 

The second set was a tight affair as Murray continued to play aggressively. With both fending off two break points in the set, they entered a tie-break, which Tsitsipas won. 

Despite the setback, Murray quickly regained momentum in the third set as he raced to a 3-0 lead and won the set 6-3. But Tsitsipas raised his level in the fourth set as he relied on depth and heavy topspin to unnerve his British opponent. 

The Greek then broke in the first game of the fifth set to establish control before he saved a break point at 2-1 with a forehand winner. Tsitsipas, who hit 19 aces in the match, then held serve for a final time to seal victory. 

Murray, who lifted his first major trophy at the US Open in 2012, was competing in his seventh tour-level event of the season, having recorded first-round victories in Cincinnati and Winston-Salem this month. It is the first time in 15 appearances that the world No. 112 has fallen in the opening round in New York.