It means Nadal remains undefeated in his 20 Grand Slam matches this year after triumphing at the Australian Open and French Open before pulling out of the Wimbledon semi-finals due to injury.
The Spaniard was playing his first match at the US Open since winning his fourth title at Flushing Meadows in 2019, and he had to overcome an early scare against world number 198 Hijikata.
“I was a little nervous,” Nadal said of his performance in the first set. “First game here in New York after three years, a night session, it’s always exciting. I got through that tough time.”
Hijikata secured the opening break with a lob at 3-3 before serving for an early lead, but Nadal began to assert his dominance in the second set – breaking Hijitaka’s serve at the first opportunity.
Nadal looked serene from there – leveling the match with another break, then taking the next two sets to clinch victory in just over three hours. He finished the game with 42 winning points and 22 unforced errors.
Without Novak Djokovic in the draw, Nadal has a good chance of winning his 23rd Grand Slam title at this year’s US Open.
“You know what, I trained pretty well all week,” Nadal said. “Then the competition is another story. You have to go through this whole process – it’s not easy.”
The 36-year-old was also questioned about taking too long between serves in Tuesday’s game, but Nadal insisted the referees did not give him different treatment and gave him no warnings for exceeding the time between services.
“I have a problem, I sweat a lot,” he explained. “When you play in these very wet conditions, we have the biggest problem today, which is that we don’t have the ball boys who bring you the towel for the past few years – you have to go to furthest place from the court to pick up the towel.
“The problem for players like me is that I sweat a lot. When you go get the towel, you’re going to have problems with the weather, so I don’t go there very often. I don’t think I have treatment different from referees at all.”
Nadal will face Italian Fabio Fognini in the second round, a player he has beaten 13 times in 17 appearances.