His Davis Cup teammate, No. 6 James Blake, beat Stefan Koubek 6-4, 3-6, 7-6 (5), 6-1 in a match that finished after 1 a.m. Sunday.
Roddick, the 2003 champion, blasted 19 aces and had 41 winners in the 84-minute match in Arthur Ashe Stadium.
"It felt good," Roddick said. "I wanted to go out
and hit the ball and be aggressive, get hold of my forehand, if
I could. I felt like I did that today."
The victory sets up a fourth-round match against
ninth-seeded Tomas Berdych.
"We play kind of similar," said Roddick, who has a 1-1
record against the Czech. "We both serve big and hit a pretty
big ball from the baseline.
"If that's the case, it's going to come down to a couple
points here and there, who converts their chances on the other
In other matches, Federer was too much for 6-foot-9 rookie John Isner in a 6-7 (4), 6-2, 6-4, 6-2 victory.
Isner used his booming serve to win the first-set tiebreaker,
and several fans barked for their favorite Georgia Bulldog. Federer
quickly figured it out and kept up his bid for a fourth straight
"I started to pick up on his serve for the second set,"
Blake's previous match stretched past midnight, too. In that one, which started Thursday night, he needed nearly 31/2 hours to get past Fabrice Santoro for his first career fifth-set victory.
"There's a million things to do on a Saturday night in New York City and for you guys to still be out here at 1 a.m., it really means a lot,'' Blake told the crowd after the match. "You make me feel like I am out -- I'm at a party here. This is a great feeling."
Against the 63rd-ranked Koubek, Blake was superb down the stretch. After making 45 unforced errors over the first three sets, he didn't make any in the fourth.
There were a total of 17 breaks of service, 10 by Blake -- and he needed one when Koubek served for the third set at 5-4. A forehand
winner allowed the American to break at love to get to 5-5, and another forehand won the ensuing tiebreaker.
From there, Blake was in command.
One minor upset came when No. 19 Andy Murray lost to 43rd-ranked Lee Hyung-taik 6-3, 6-3, 2-6, 7-5. Lee, in the U.S. Open's fourth
round for the first time since 2000, will meet Davydenko.
Despite swirling winds, Roddick had no trouble with his
serve against Johansson, landing 68 percent of his first
attempts. He also had just 11 unforced errors.
"The wind is always tough out there," Roddick said . "It
blows. You feel it on the ball even more so than when you're
just walking around."
Roddick said he saw television highlights of his Open
triumph in the locker room "pretty much every time" he went on
court at Flushing Meadows.
"It's nice to see it but at the same time it makes you want
it again," he said.
Reuters and The Associated Press contributed to this report.