Timothy A. Clary, Getty Images
Roger Federer fires back a return shot in the third round of the U.S. Open on Sunday.

NEW YORK — As if trying to remind himself and everyone else where he's been and where he's quite certain he'll return, Roger Federer thrust his right fist overhead and pointed skyward with his index finger.

The universal gesture for No. 1.

As Federer made that signal, the 1970s song "Still the One" by Orleans rang out through Arthur Ashe Stadium on Sunday, marking the end of the four-time defending champion's 6-3, 6-3, 6-2 victory over 28th-seeded Radek Stepanek in the U.S. Open's third round.

Actually, for the first time in a while, Federer is not No. 1 — in the seedings for the hard-court Grand Slam tournament or in the ATP rankings. Those honors belong to Rafael Nadal, who beat Federer in the lopsided French Open and epic Wimbledon finals and last week ended his record 237-week stay at the top.

Federer harbors no doubts that he can re-establish his ranking and his reputation among opponents, both built on the strength of 12 career major singles titles, two shy of Pete Sampras' career record.

"That's the advantage I have. If I were to win a big tournament again, one of those Slams, whatever, right away I have the invincibility factor again, which is great for me," he said. "So that's what I'm working for. I was that close in Wimbledon, so I hope to go a step further and win it this time."

It's been a poor-by-his-standards — and, let's be clear, only by his lofty standards — season for Federer, whose 12 losses already are more than he absorbed in any entire year from 2004-07. His two titles, at minor events, are his fewest entering the U.S. Open since 2002.

On the other hand, Federer did reach the semifinals at the Australian Open before losing to eventual champion Novak Djokovic — who was scheduled to play his U.S. Open third-round match late Sunday night — and was the runner-up at the other two major tournaments.

"I would love his bad year. ... The guy has the best four-year run ever, and we're all sitting here in shock that it's not the best five-year run ever. We have to use a little bit of perspective here as far as how good he's been," said Andy Roddick, the last man other than Federer to win the U.S. Open, back in 2003, and his potential semifinal opponent this year.

"If you have to hear about anything every day, you start thinking about it a little bit, and maybe that's where he's at," added Roddick, who reached the fourth round by beating No. 31 Andreas Seppi 6-2, 7-5, 7-6 (4).

Roddick will play No. 11 Fernando Gonzalez or Jarkko Nieminen.

Federer's next opponent is No. 23 Igor Andreev of Russia, who beat No. 13 Fernando Verdasco of Spain in straight sets. In other men's third-round matches, No. 5 Nikolay Davydenko eliminated No. 26 Dmitry Tursunov, and qualifier Gilles Muller fashioned a 6-7 (3), 3-6, 7-6 (5), 7-6 (6), 7-5 upset of No. 18 Nicolas Almagro.

The women are a round ahead, and No. 2 Jelena Jankovic reached the quarterfinals by coming back to beat No. 21 Caroline Wozniacki 3-6, 6-2, 6-1. Jankovic is among five women with a shot at reaching No. 1 in the rankings by tournament's end.

She, though, has something else on her mind.

"It's a goal," Jankovic said, "but I want to win a Grand Slam."

Another woman in the chase for No. 1 — and also without a major championship title — is Olympic gold medalist Elena Dementieva, who faced Li Na at night.

Australian Open champion Novak Djokovic has reached the fourth round of the U.S. Open with a tougher-than-expected victory over 30th-seeded Marin Cilic.

Djokovic needed nearly four hours to get past Cilic 6-7 (7), 7-5, 6-4, 7-6 (0) Sunday night.

Jankovic will meet No. 29 Sybille Bammer, who got past No. 12 Marion Bartoli 7-6 (3), 0-6, 6-4 in a match that lasted 3 hours, 5 minutes — believed to be the longest women's match, by time, in U.S. Open history.

"I didn't even really sweat," Bammer said. "I could have played longer."

Muller looked as though he could have, too, even though his match against Almagro stretched beyond four hours.

Muller never had come back from a two-set deficit in his career before doing so in the second round against Tommy Haas. Now he's done it twice in a row — despite winning a dozen fewer points than Almagro, 187-175, and making 25 more unforced errors. And Muller broke serve only once all match, in the final game. But he also was broken only once, late in the second set, and served 38 aces.

Muller is the only man from Luxembourg to play in a Grand Slam tournament in the 40-year Open era — and now the first man or woman from the country to reach the fourth round.

"I'm the first one actually to do everything. I mean, that's not my goal — to be the best in Luxembourg," he said.

This isn't his first moment in the spotlight at Flushing Meadows: Muller stunned Roddick in the first round in 2005. Since then, Only Federer has beaten Roddick at the U.S. Open, in the 2006 final and the 2007 quarterfinals.

Those are part of Federer's 30 consecutive victories in the hard-court major championship. The three wins this year have all come in straight sets, and Federer was truly tested only briefly by Stepanek.

Serving while up 4-2 in the first set, Federer got broken when Stepanek smacked a forehand passing winner on the run, then skipped to the changeover windmilling his right arm.

Federer, though, broke right back at love.

One last gut-check came when Federer double-faulted twice at 1-1 in the third set, setting up a break point for Stepanek. But Federer erased that with a 112 mph service winner and followed with a 128 mph ace, opening a run in which he won the last 11 points on his serve.

"I guess it's just nice to play well," Federer said. "Pretty simple.

One of his surprising 2008 setbacks came against Stepanek in May on clay in Rome.

The surface, the city and the stature of the tournaments were all quite different Sunday. Still, it made sense to ask Stepanek whether Federer was better on this day than on that one.

"I don't know if he's better, but definitely I think he's more hungry than he was a couple of months ago," Stepanek said.

Why?

"For the last four, five years, everything went his way. And suddenly, you know, there's somebody who took it away from him," Stepanek said. "And I think Roger is competitive enough that he wants it back. And he knows that he has to get better."