Shelton was the first player of this year’s tournament to play on the iconic Arthur Ashe show court, taking just over two hours to wrap up victory.
The former semi-finalist is in good form, having won his first ATP Masters 1000 title at the Canadian Open earlier this month.
“The US Open is the pinnacle of tennis for me and what I dreamed about as a kid,” Shelton said.
“It is starting to feel like home for me.”
Shelton beat Fritz in the semi-finals on his way to the title in Toronto and the two could potentially face one another in the last four in New York.
But Shelton, 22, remained cautious when asked if he could go far at this year’s tournament.
“As soon as you start looking ahead of yourself you stumble over your own feet so for me it is one day at a time,” he said.
“We are here for the long haul and I am looking forward to it.”
Fritz, who lost out to world number one Jannik Sinner in last year’s final, has also performed well in recent months.
He reached the semi-finals at Wimbledon and won grass-court titles at Eastbourne and Stuttgart, putting him in the sort of form that suggests he can go far at the year’s final Grand Slam.
Fritz will face either Sebastian Beez or qualifier Lloyd Harris in the second round, whilst Shelton will take on Spain’s Pablo Carreno-Busta.
