Murray, who has suffered badly with cramping during the hard-court season, earned a 7-5, 6-3, 6-3 win over 24th seed Cerundolo to advance to the second round, where he will meet 20-year-old American wildcard Emilio Nava.
The 35-year-old won a hard-fought opening set, with both players breaking serve in the first two games. An unusual incident occurred in the ninth game when, in an act of sportsmanship, Cerundolo forfeited a point he had been awarded despite the ball bouncing twice. Murray, who thanked Cerundolo for his honesty, went on to win a crucial break point to take the first set 7-5.
The Scot found his task much easier in the second set as he raced to a 5-0 lead, eventually taking it 6-3. Murray followed up with a dominant 5-1 lead. Cerundolo would break serve once more, but it proved not to be enough, as Murray served out to take the final set 6-3 and a place in the next round.
“It felt like five sets to me, it was tricky conditions, very humid and hot,” Murray said.
“But I’m happy with the way I got through that one. He has had a brilliant year, I knew I had to play well and I did that in the important moments.”
Murray’s appearance at the US Open this week marks a decade since he won his first Grand Slam at Flushing Meadows in 2012.
He has has two men’s singles titles at Wimbledon (2013 and 2016) and the London 2012 and Rio 2016 Olympic Games.
On Cerundolo’s sportsmanship in the first set, Murray praised his opponent for his honesty, adding that he would not have expected him to forfeit the point.
“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 it 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.”