Roger Federer [Images] goes into next week's US Open as the overwhelming favourite as he bids to become the first man in the modern era to win the title for a fourth consecutive time.

But though he is high on confidence after winning his 50th career title in Cincinnati last weekend, the world number one has one name nagging away at him.

Rafael Nadal [Images].

Victory in New York would not only make Federer the first man since American Bill Tillden in the 1920s to win four titles in succession, it would also see him win three of the four Grand Slam events for the third time in four years.

A 12th Grand Slam crown is also on the line for Federer, just two short of the record held by Pete Sampras.

Nadal ended any hope of a Federer Grand Slam by beating him in the French Open final and pushed him to five sets in the final at Wimbledon. The Swiss had no doubts about who will be his main rival over the next two weeks.

"Even though now people talk about (Novak) Djokovic, for me Nadal is better, a lot better to be honest," Federer told Reuters in an interview.

"If I don't win the US Open I expect him to win it."

Djokovic beat both Nadal and Federer to win the Montreal Masters the week before Cincinnati but Federer said the Spaniard was a cut above the rest.

IMPRESSIVE STUFF

Federer said Nadal was being underestimated, especially by the media.

"There's no such thing as a specialist on clay now. Maybe it's your best surface but then you can always play well on the hard courts, and even grass today," he said.

"That's why I am not surprised at all at how good he is -- what has surprised me that at his young age, he's been able to do it for so long.

"That's impressive stuff and something that I wasn't able to do. That's why I have high respect for him.

"It's almost impossible for him to be as dominant on hard courts as he is on clay because hard courts is just a different ball game, but it (his main rival) is Nadal."

After equalling Bjorn Borg's record of five consecutive Wimbledon titles in July, Federer took a brief rest and then set to work in the heat of Dubai to prepare for the summer.

"I'm very happy that my hard work paid off in Dubai, right away," he said.

"Taking a break right after Wimbledon is nice, for my private life, for my mental part, for the physical strain I went through from the claycourt season and the grass, but then at the same time you'd like to carry over your confidence into another tournament.

"That's why it's always important to play well right away -- to forget about Wimbledon and look forward. I've had my best summer actually, playing in the finals (in Montreal) and winning (in Cincinnati), so hopefully I can keep it up at the Open."

The top seed will meet qualifiers in both the first two rounds in New York, but Federer said he was wary of every opponent.

"Everybody knows that a qualifier can be tough because he could make his break," he said.

"Ok, people wouldn't expect me to lose in the first round to someone ranked 150 or 200 in the world but it has happened in the past, so you have to always be wary.

"I've been on a great run at grand slams and best-of-five sets should favour me, but with the knockout system you never know."

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