NEW YORK - Right from the start, Roger Federer looked very little like, well, the Roger Federer who routinely reached the final weekend at Grand Slam tournaments.
In the opening game of his fourth-round match at the U.S. Open, the owner of 17 major titles got passed at the net twice, sailed a backhand long, then missed two forehands to get broken. In the second game, the man who has spent more weeks ranked No. 1 than anyone else dumped a backhand into the net, then shanked two other backhands several feet wide.
No longer the dominant presence he once was, Federer lost in the round of 16 at Flushing Meadows for the first time in a decade, surprisingly beaten 7-6 (3), 6-3, 6-4 by 19th-seeded Tommy Robredo of Spain on Monday night.
"I kind of self-destructed, which is very disappointing," said Federer, who made 43 unforced errors and managed to convert only two of 16 break points. "It was a frustrating performance."
Only the latest in a series. This caps a poor-by-his-standards Grand Slam season for Federer, whose record trophy collection includes five from the U.S. Open.
He exited in the semifinals at the Australian Open in January, the quarterfinals at the French Open in early June, and the second round of Wimbledon - against a player ranked 116th, to boot - in late June. That ended Federer's record run of reaching at least the quarterfinals at 36 consecutive Grand Slam tournaments.
Now, thanks to Robredo, Federer has a new, unwanted streak: Two consecutive losses before the quarterfinals at majors.
This is the first season since 2002 that Federer did not reach at least one final at any of the four Grand Slam tournaments. That year also marked the last time Federer was ranked lower than he is now at No. 7.
"The story of my life: When I lose, people are shell-shocked to see me play this way," Federer said.
Heading into Monday, the buzz at the U.S. Open was all about looking ahead to a potential quarterfinal between Federer and his nemesis, Rafael Nadal. Owners of a combined 29 Grand Slam trophies, they have played each other 31 times - including in eight major finals - but never in New York.
Federer's loss means they won't fix that gap in their rivalry this week. When Federer's match was ending, the second-seeded Nadal was just getting started in Arthur Ashe Stadium, and the Spaniard wound up improving to 19-0 on hard courts in 2013 with a 6-7 (4), 6-4, 6-3, 6-1 victory over 22nd-seeded Philipp Kohlschreiber of Germany.
Nadal, who won the 2010 U.S. Open but missed the tournament last year with a left knee injury, erased the only break point he faced against Kohlschreiber and has not lost a service game so far through four matches.
"It was very, very tough conditions out there. Very humid," Nadal said. "I sweat too much tonight."
In the three women's matches that were played Monday, No. 10 Roberta Vinci and unseeded Flavia Pennetta set up an all-Italian quarterfinal with victories. Vinci beat yet another woman from Italy, 136th-ranked qualifier Camila Giorgi, 6-4, 6-2, while Pennetta defeated No. 21 Simona Halep of Romania 6-2, 7-6 (3).
Azarenka or Ivanovic will face Daniela Hantuchova of Slovakia, who got past American wild-card entry Alison Riske, a 23-year-old who grew up in Pittsburgh, 6-3, 5-7, 6-2.
In men's action, No. 4 David Ferrer of Spain, the runner-up to Nadal at the French Open this year, moved on by beating No. 18 Janko Tipsarevic of Serbia 7-6 (2), 3-6, 7-5, 7-6 (3). In the quarterfinals, Ferrer will play No. 8 Richard Gasquet, who entered the day 1-15 in fourth-round Grand Slam matches but erased a match point and withstood 39 aces from No. 10 Milos Raonic to win 6-7 (4), 7-6 (4), 2-6, 7-6 (9), 7-5 on Court 17.
A long line of fans snaked across the grounds when Federer-Robredo was moved from Ashe to much smaller Armstrong, which holds about 10,000 spectators and has a lot less room separating the playing surface from the stands. Federer, accustomed to playing in Ashe, last competed in Armstrong in 2006.
He said that was not a factor in Monday's outcome, though. The blame, instead, belonged with his inability to hit his strokes the way he wanted.