Rafael Nadal believes he can build momentum towards the latter stages of the US Open, having overcome Taro Daniel in four sets in Thursday's second-round encounter.

The world number one trailed a set and a break to the Japanese world number 121 but eventually rallied to win 4-6 6-3 6-2 6-2.

Nadal and long-time rival Roger Federer are hot favourites for the title at Flushing Meadows with Andy Murray, Novak Djokovic and Stan Wawrinka all missing.

With a thinned-out field, Nadal can perhaps afford to ease himself into the competition, but he is seeking a swift improvement on Thursday's error-strewn display against Daniel in New York.

"I think the speed was positive," he told a news conference. "It was a good fight. I think I improved. The last two sets I played better, and that's important for what's coming, no?

"But, of course, it is a day to be satisfied. Days that you're not playing well, that makes the difference: win when you don't play very well. That give me the possibility to play better.

"I hit around 40 winners. That's not a bad number. But 35 unforced errors, that's a bad number for me.

"I need to fix that. I need to improve that. I need to play with the feeling that when I'm hitting the ball, I'm not going to miss and with high intensity. That is the way I need to play if I want to have chances of success here. I'm going to work to make that happen."

The toils of the ATP Tour have taken numerous victims, with Kei Nishikori and Milos Raonic adding to the high-ranking absentees, but Nadal is feeling fresh in a year which has seen him put long-term fitness concerns behind him to scale the heights of men's tennis again.

"I don't feel fatigue," he said. "I feel positive. I feel hungry to keep playing. 

"I'm excited for being here. Not tired at all. Is the last big, big event of the year. 

"I want to try all the things that are in my hands to give me a chance. That's what I am doing: working with the right intensity, with the right attitude, then in the match trying to do the same.

"First two matches have been, of course, not great, but I am in the third round. That's the most important thing."

Nadal will take on Leonardo Mayer in the third round.