Roger Federer was able to overcome a sloppy performance on Friday against unheralded Brazilian Thiago Alves to reach the third round of the US Open.
The second-seeded Federer nearly had as many unforced errors as winners in a tougher-than-expected 6-3 7-5 6-4 victory over the 26-year-old Alves, who is ranked 137th in the world.
Number three seed Novak Djokovic of Serbia, the reigning Australian Open champion, also was tested but fought off unseeded American Robert Kendrick 7-6 (10-8) 6-4 6-4.
Eighth-seeded American Andy Roddick perhaps had the toughest test of all Friday, battling to defeat Latvia's Ernests Gulbis 3-6 7-5 6-2 7-5 in just under three hours.
"Tonight was one of those ones that I won on effort," said Roddick, who was the 2003 champion here. "Thanks to (the crowd), you kept me in it when I was losing it. So, thank you."
Much like Federer, Roddick is not having the type of season he expected in 2008.
After a great start to the year that included his engagement to model Brooklyn Decker, Roddick lost in third round at the Australian Open, sat out the French Open and suffered a second-round exit at Wimbledon.
He was in danger of continuing that dismal pattern here, dropping the first set and falling behind 5-4 in the second. Roddick was so flustered, he even smashed his racket on the court in a fit of anger.
But the American star bounced back, breaking Gulbis' serve to make it five-all in the second. Roddick then took that set and won the first three games of the third to take control of the match.
"He definitely outplayed me for the (first part of the match), but the clock struck 12 (midnight EDT) and I started playing like a 26-year-old," said Roddick, whose birthday is Saturday.
Trying to salvage one Grand Slam in a disappointing year, Federer advanced to a third-round meeting against either No. 28 seed Radek Stepanek of the Czech Republic or Australian Chris Guccione.
"These are the early-round matches, so it will only get better from here," said Federer, who won his 600th career match. "I was never really in danger, so it was actually pretty good for me."
Still, Friday's performance may have raised more questions about the overall state of Federer's game. He had 54 winners but committed 46 unforced errors and converted only four of his 15 break points.
The 21-year-old Djokovic, who seemed to show no ill affects from the ankle injury he suffered in the third set of his first-round victory over Frenchman Arnaud Clement, saved a set point in the first set tiebreak against Kendrick after squandering a 6-2 lead.
Djokovic, who received treatment on both knees after the first set, eventually wore down Kendrick with 34 winners and only 13 unforced errors. The American had 46 winners but 30 unforced errors.
In an earlier second-round match Friday, number 1 seed Fernando Gonzalez of Chile survived an injury scare to get past American Bobby Reynolds 7-6 (8-6) 6-4 6-4.
Down 2-0 in the second set, Gonzalez suffered a sprained left ankle. But he recovered after getting his ankle re-taped during an injury time-out.
Also reaching the round of 32 was number five seed Nikolay Davydenko of Russia, who ousted Argentina's Agustin Calleri 6-4 6-4 7-6 (7-2).
Other seeded winners included number 11 Fernando Gonzalez, number 13 Fernando Verdasco, number 15 Tommy Robredo, number 18 Nicolas Almagro, number 19 Jo-Wilfried Tsonga, number 23 Igor Andreev, number 26 Dmitry Tursuno, number 28 Radek Stepanek, number 30 Marin Cilic and number 31 Andreas Seppi. Seppi will take on Roddick in the third round.
Unseeded players to advance were Finland's Jarkko Nieminem and Gilles Muller of Luxembourg.