Top seed Dinara Safina of Russia reacts to a point durng her match against Petra Kvitova of the Czech Republic. (Don Emmert/AFP/Getty Images)

A Saturday filled with upsets at the U.S. Open tennis tournament extended into Sunday with top-seeded Dinara Safina of Russia eliminated in Round 3.

Petra Kvitova, the 72nd-ranked women's player, needed two hours 34 minutes to dispose of Safina 6-4, 2-6, 7-6 in a match that ended shortly before 1 a.m. ET at Armstrong Stadium in New York.

On the men's side, Spain's Tommy Robredo defeated No. 21 James Blake of the United States 7-6 (2), 6-4, 6-4 early Sunday morning.

Safina's defeat marked the first time this year she failed to reach at least the semi-finals of a Grand Slam tournament.

She will retain the world No. 1 ranking despite Saturday night's loss but will also remain without a major title.

Safina struggled mightily in a pair of three-set victories to start the tournament, averaging 43 unforced errors and 13 double faults in the first two rounds.

She cleaned things up a little bit against Kvitova — 39 unforced errors and nine double faults — but was on the defensive for most of this match, which was moved from Arthur Ashe Stadium because of the late-running afternoon session.

Hewitt drops 14th straight to Federer

Elsewhere, Lleyton Hewitt of Australia came away empty against Roger Federer again on Saturday, despite outplaying him for the better part of three sets at the U.S. Open in Flushing Meadows, N.Y.

The five-time defending champ Federer advanced to the fourth round with a 4-6, 6-3, 7-5, 6-4 victory at Arthur Ashe Stadium, a match that lasted 2 ½ hours.

Federer has now won 37 consecutive matches at the Open, last losing in 2003 to David Nalbandian.

The win didn't come easy for the Swiss star. He committed 23 errors en route to dropping the first set, and gave up 14 break-point chances to Hewitt.

The Australian was able to capitalize three times, a ratio not quite good enough to topple the best player in the world.

"You know how good he can play when he's on, and you try to take advantage of those small opportunities when they come," said Hewitt. "You're not going to get a lot, obviously."

Hewitt, the 2001 Open champion, was up 7-2 in the head-to-head series between the players at one point but has now lost the last 14 battles.

Federer got off to a strong start, and was up 4-2 in games and 40-love before Hewitt rallied in the first.

Hewitt put away his fourth break point at 4-4 in the first and then watched as Federer hit long to end the set.

1st-serve struggles

Federer got back on track in the second with an early break but was hit-or-miss on his first serve well into the third set.

The match turned when he broke Hewitt's serve at 5-5 in the third.

Federer capped off the set on one of the best points of the match. He needed a drop shot, volley at the net and overhead to finally put away the dogged Hewitt.

"I just had to believe that I could still turn this around," said Federer. "And with the great streak I have against him, I knew that if I could get back into the match, then I could get back on a roll, because I've done it so many times against him."

Federer roared out to a 4-1 lead in the final set, a margin comfortable enough that a lackadaisical effort on his serve in the eighth game of the set didn't hurt.

He will await the winner of Saturday night's match between James Blake of the United States and Tommy Robredo of Spain.

Elsewhere, No. 4 seed Novak Djokovic of Serbia needed 3 1/2 hours and four sets to finally overcome Jesse Witten of the U.S., ranked 276th in the world.

No. 6 Nikolay Davydenko of Russia also advanced, defeating Marco Chiudinelli of Switzerland in straight sets.

In second-round men's doubles, Toronto's Daniel Nestor and partner Nenad Zimonjic beat Aisam-Ul-Haq Qureshi of Pakistan and Finland's Jarkko Nieminen 7-6, 6-3.

With files from The Associated Press