Last year's runner-up Kei Nishikori of Japan is out of the 2015 US Open after 41st ranked Benoit Paire defeated the fourth seed 6-4, 3-6, 4-6, 7-6 (6), 6-4 here.
"It's always very sad to lose in the first round, but I think he was playing good tennis," Nishikori was quoted as saying by Xinhua.
"I don't think I played badly. It's never easy on the first match. He's a good player. I will try to think about the next one, and I hope I can come back strong next year."
"I had a really good serve today," Paire said. "I saved two match points so I'm really lucky."
Paire broke early in the first set to win it 6-4 before Nishikori won sets two and three. But the Frenchman held firm in the fourth, winning a tiebreak and then breaking for just the second time in the match and holding serve to seal the victory.
