A “nervous” Norrie was worried about being first on court at 11:00 local time and need to fuel up before playing an opponent who was ranked inside the top 20 a year ago – and against whom he had lost three of four past meetings.
Ultimately the 30-year-old did not need to be overly concerned, as Norrie was leading 7-5 6-4 when Korda, 25, ended the match early.
American Korda only returned to tour action last week following a near three-month shin stress fracture lay-off.
He called a medical timeout at the start of the second set against Norrie when he appeared to be struggling with an abdominal issue.
Although Korda persevered for the remainder of the set he was unwilling to go any further, sending Norrie through to face either Argentine Francisco Comesana or American Alex Michelsen.
Norrie, who withdrew from the 2024 US Open with an arm injury, made his debut at Flushing Meadows in 2017 but still feels the nerves in New York.
“I was very nervous for the match,” said Norrie.
“Playing a Grand Slam match at 11am and trying to get rice down at 10am is not easy!”
On Korda’s retirement, Norrie said: “I feel for Sebastian. He’s been out the whole summer, he’s an amazing talent and he’s beaten me the last few times we’ve played.
“It’s tough to see him ending like that.”