World No 1 Rafael Nadal battled back after dropping the first set Thursday to subdue Japan’s 121st-ranked Taro Daniel and reach the third round of the US Open.

The 31-year-old Spaniard won his ATP-best 51st match of the year by 4-6, 6-3, 6-2, 6-2 over the 24-year-old New York native, who fell to 0-4 against top-10 rivals.

The two-time former champion in Flushing Meadows looked to be struggling against Daniel up until the early moments of the second set. Daniel led Nadal by a break at 2-1 in the second set, before the match changed course. Nadal broke back the Japanese as he tried to consolidate a break, before breaking Daniel for the second time in the set to level the match at a set-all.

The third and fourth sets were pretty much one-sided in favour of Nadal as Daniel struggled to up the ante of his momentum. There wasn’t, however, nothing much that he could do as Nadal swept past him in the match that lasted merely seven minutes short of the three-hour mark.

“It’s a very important victory,” Nadal said. “It’s true I didn’t play very well tonight but it’s true I’m through to the third round.”

The Mallorcan finished 40 winners and 35 unforced errors to Daniel’s 26 winners and 38 unforced errors. The 15-time Grand Slam champion who captured his 10th French Open crown in June, will face 59th-ranked Argentine lucky loser Leonardo Mayer on Saturday for a berth in the last-16.

Mayer is 0-3 against Nadal, losing most recently in the third round of his 2014 title run at Roland Garros.

“I didn’t play very well, but tomorrow I will work hard to find better feelings because I know I can do much better,” added Nadal.

The highest-seeded obstacle in Nadal’s path to the semi-finals, and a possible first-ever US Open matchup with long-time rival Roger Federer, is Belgian ninth seed David Goffin.

But the tantalising prospect requires three more wins for each of them.

“All the matches are difficult but especially here as everyone wants to play their best and if you don’t play your best it will be very difficult,” Nadal said.