It became quite clear after his scratchy and sweaty 6-2, 5-7, 7-6(2), 6-3 fourth-round win over the pumped-up young American Sam Querrey that Rafael Nadal knows that he's in a heck of a fight to win his first US Open title.

It's been quite some time that the Spaniard has strained as hard as he did in having to overcome Querrey, as he consistently lacked depth on his strokes, had his serve broken four times (he faced 16 break points) and clearly lacked in overall confidence.

Part of the credit for that has to go to Querrey, who stepped up his game in a big way, firing nearly untouchable serves, hardstruck forehands and consistent backhands.

But Nadal didn't play his best and knew it.

“I just go and try my best ever match,” Nadal said. “It's not in Grand Slam; in every tournament you have one bad day. That's the normal thing. Important thing is win. When you are playing not your best, the important thing is win. I did today, so I have a chance for practice tomorrow and for play another time on Wednesday. So that's the important thing. I'm very happy for that.”

It was not the Nadal who has dominated the tour since April, dropping only two matches. He's won eight titles this year, two of them being Roland Garros and Wimbledon, one of them being the Olympics, and three of them being Masters Series crowns. He's having one of the finest stretches of any player ever and should he win the US Open, he'll be the first man since Rod Laver in 1969 to win Roland Garros, Wimbledon and the US Open in succession--no small feat.

While Nadal came into the tournament a bit tired after his gold medal run in Beijing, he appears to be in better shape than he was last year, when he was completely tapped out and dealing with minor leg injuries, he was run ragged by David Ferrer in the fourth round. He's not as spry as a kindergarten student onhis first day at school, but his strong frame should be good for at least three more matches.
“I am not in the freshest moment in my life, but I am fine,” he said. “So important thing, I am there. I feel very well physically. The last few years, very happy for that. For sure I'm a little bit worried about the tennis, because it's moving always in the way for play more and more in hard surfaces. It's more difficult for the body. You go to the trainer's room. When I go, I am never alone, so that's not a good news for the sport.”

Perhaps most importantly, the 22-year-old is more experienced than he was two years ago, when Mikhail Youzhny went to town on him. He may be a young guy, but he's been playing high-level matches for four years, which is why after a spotty first quarter of the year, he was able to regroup and snare Roger Federer's top ranking a few weeks ago.

Becoming No. 1 just isn't about talent and weapons, its also about heart ad know-how and he has plenty of that. Plus, his defense and increased variety are more than difficult to contend with.

“ I guess like the surprising thing is that backhand chip,” said Querrey. “He does a great job of just going over there and really just kind of getting balls back and getting balls back. For the most part, they're pretty deep. It's tough, because he gives you that chip and he almost tempts you to come in. You can't just come in on any ball against him. You have to put it pretty much in one of the corners, otherwise he's going to pass you. Sometimes if you put it in one of the corners he's going to pass you. He's kind of just edging you on a little bit. It's tough to deal with.”

Nadal has three matches in front of him and one will be easy. He'll confront the red-hot American Mardy Fish in the next round, who is confident that his attacking style of serve and volley and slap and charge is the only way to beat him.

"I feel like a guy with my style of play is someone that he doesn't want to see," Fish said. "Rafa is playing so well and he's just so solid from the baseline. He's so confident and he moves so well. You got to be able to finish points quickly. He's going to last longer than anybody. He wants to keep the points as long as possible and run the guys down, kind of body blow after body blow. If he's on the other side of the net, I don't intend to let him do that. I'm going to come in, not necessarily Kamikaze-type tennis, but I'm going to try to keep the points as short as possible if it is him."

Nadal has to play more offensively if he's going to win the tournament. He allowed Querrey to dictate to him much too often. While a contest against Fish that features shorter point and matches Fish's serves and volleys against his returns and passing shots might be easier on his legs, no player since Lleyton Hewitt in 2001 has won this tournament primarily counterpunching. Nadal is capable of imposing a brutish inside-the-baseline game, but has to convince himself to do so.

He got a wake-up call against Querrey, and now he'll have to bait his hook to catch the squirmy Fish.

“He's a dangerous player in hard court,” Nadal said of Fish. "Right now he's playing very well. Big serve, very good backhand, good volley. So he's playing with big confidence, and I have to play very well if I want to win. Hopefully I have to play my best for the last part of the tournament.”