Andy Murray provided one of the upsets of the US Open's first round when he made his way past No.24 seed Francisco Cerundolo of Argentina 7-5 6-3 6-3, but it wasn't without controversy.
The 35-year-old hadn't been expected to run deep into the US Open bracket, but muscled his way past the Argentinian thanks in part to his opponent conceding a point the chair umpire had otherwise ruled in his favour.
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Murray was furious at the chair umpire during a key point in the first set, when Cerundolo appeared to have successfully made it in on a Murray drop shot - only for replays to show the ball had clearly bounced twice.
Chair umpires are prohibited from using video replays to check for correct decisions, with each player's limited use of the Hawkeye challenge system the only method by which a call can be overturned during a match.
Serving at 4-5 down in the first set, Cerundolo charitably conceded the point, putting himself down 0-30 in the game, though he would go on to hold his serve but lose the set.
Murray later gave credit to the Argentinian for his sportsmanship, with both players suggesting the ATP look into allowing umpires to refer to video review for their own purposes if required.
"What he did was brilliant, and I don't think that loads of players on the tour would have done that. Fair play to him," Murray said.
"I said that to him at the net. You know, he didn't have to do that either.
"I think in those situations it's sometimes difficult for the player who picks the ball up to know exactly but the player who is receiving the ball, they know almost immediately.
"The ball when it comes with topspin in those situations, it's almost always because there has been a double bounce or the ball has been hit into the court, creating the topspin. You know immediately.
"So when the ball came over, I knew that it had bounced twice, which I had obviously said to the umpire. Yeah, I think there is an argument for (video review) to be used in those situations, for sure.
"But for me it was clear, and like I said, he didn't need to do that. Yeah, fair play to him for giving me the point."
Calls for ATP to adopt video review after controversial point conceded
For his part, Cerundolo said he wouldn't feel comfortable as a professional to keep the point.
He said as a competitor, conceding the point to Murray was the right thing to to, adding that chair umpires should have access to all potential resources to ensure accurate calls are made.
"They should have that replay to check if it was double bounce or not. That [would] help us," Cerundolo said.
"I had to give him the point. Of course I will do it today and I will do it many more days. If it happens again.
"It's how I am. I'm not going to steal a point. Of course I'm not gonna win a point if I lost it.
"I had no idea that it was a double bounce. When I just come down and see the screen I realised that it was a double bounce, I had to give him the point."
Elsehwere, on the same Arthur Ashe Stadium court where Serena Williams was set to begin what could be the final tournament of her career, the top-seeded Daniil Medvedev looked just as strong as he did in sweeping past Novak Djokovic in last year's decider for his first major title.
Medvedev crushed American Stefan Kozlov 6-2 6-4 6-0 in just over two hours to set up a match with Arthur Rinderknech of France. The world No.1, who was denied entry to the last grand slam at Wimbledon due to his homeland's invasion of Ukraine, is seeking to become the first player to retain the title since Roger Federer from 2004-08.
"I need to be at my best on Wednesday and I'm going to try to make it," Medvedev said.
Stefanos Tsitsipas was the highest seed eliminated on day one. The fourth-seeded Greek dropped the first 11 games to Colombian qualifier Daniel Elahi Galan before falling 0-6 1-6 6-3 5-7.
Two other past champions also had short stays. Dominic Thiem, the 2020 winner fell to Pablo Carreno Busta in four sets while 2016 winner Stan Wawrinka retired from his match against Corentin Moutet after losing the first two sets.
Elsewhere, fifth seed Casper Ruud and 13th seed Matteo Berrettini progressed in straight sets.
Sixth seed Felix Auger-Aliassime of Canada enjoyed a four-set victory, as did Brandon Holt. The son of two-time women's champion Tracy Austin upset 10th seed and fellow American Taylor Fritz also in four sets.
Compatriots Tommy Paul, Sebastian Korda and J.J. Wolf were also victorious and qualifier Wu Yibing became the first Chinese man to win a US Open match in the professional era, upsetting No.31 seed Nikoloz Basilashvili of Georgia 6-3 6-4 6-0.
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