A SEMI-FINAL between Rafael Nadal and Roger Federer at the US Open continued to look a long way away as the Spaniard followed his rival in labouring into the third round.

Federer has been taken to five sets in both his first two matches at Flushing Meadows, with the night session on Thursday delayed by his latest struggle against Mikhail Youzhny.

Nadal did not begin his clash against Japan’s Taro Daniel until after 9.30pm and it was nearly three hours later when he was finally able to celebrate a 4-6, 6-3, 6-2, 6-2 victory.

The top seed was certainly more impressive than Federer, with his forehand warming up nicely as the match went on, but the feeling remains that this is the most open men’s grand slam in years.

Nadal, who next meets Argentina’s Leonardo Mayer, said: “All the matches are difficult and especially here. Everybody wants to play the best and if you don’t play your best it’s very difficult.

“It’s a very important victory. It’s true I didn’t play very well but it’s true that I’m through to the next round.

“I was a set and a break against but I felt in the first set I had a lot of opportunities. I was thinking ‘let’s keep going and hopefully I’m going to convert one of these’.

“I need to improve a lot of things but I am here to try to improve every day. I’m going to work tomorrow to find better feelings and I really believe I’m going to do it much better.”

The themes of the tournament so far have been shocks and unexpected battles for the favourites but everything pointed in Nadal’s favour here.

Daniel, ranked 121, had never beaten a top-10 player nor reached the third round of a grand slam while he needed five sets to battle past Tommy Paul on Wednesday as Nadal put his feet up. The 24-year-old also arrived in New York having won just one of his previous eight matches.

Yet for a set and a half he more than matched the world number one, playing with fearless aggression and intelligence.

Daniel was under pressure in every service game but Nadal was unusually wasteful and, as he retreated further behind the baseline, his opponent struck.

Daniel, who is half-American, had plenty of support from the Arthur Ashe crowd as he broke for 5-4 and then survived a couple of nervy moments to serve out the opening set.

When he broke Nadal again to lead 2-1 in the second, the unthinkable seemed possible, but the world number one found his trademark forehand down the line just in time.

All Nadal’s opponents quickly learn that approaching the net on that wing risks paying a heavy price and Daniel was twice broken in just such a fashion.

As Nadal grew stronger, Daniel began to tire, and by the fourth set it was a matter of how long the Japanese player would be able to hang on. A double fault on break point in the fifth game heralded the beginning of the end, with Nadal wrapping up victory at 12.29am.

Federer, meanwhile, insisted his US Open campaign is heading in the right direction despite his second five-set struggle of the tournament.

Only two players in the Open era have won grand slam titles after being taken to five sets in their first two matches – Boris Becker in Australia in 1996 and Gaston Gaudio in France in 2004.

But, as he invariably does, the 36-year-old saw the positive side, saying: “These five-set battles are actually quite a lot of fun. I feel quite warmed up by now.

“I still believe I’m going to pick up my game and become just more consistent, because I’m not playing all that bad. It’s just that I’m going a bit up and down in waves throughout the match.

“So clearly I’m happy how I felt after the first round, because that was the scary bit. But that’s passed now. Now I can just look forward to play tennis.” With a bit of fatigue, that’s okay. I’ve done that hundreds of times.”