FLUSHING MEADOWS, N.Y. -- American Andy Roddick is on a collision course with Roger Federer at the U.S. Open after the big-serving American posted a fourth-round victory on Labor Day.

Another American was not as fortunate on Day 8, as James Blake fell to German Tommy Haas in five sets.

The fifth-seeded Roddick was leading big Tomas Berdych when the Czech retired in the second set, with the American leading 7-6 (8-6), 2-0. Berdych, who called for a trainer early in the first set, had a set point in the first-set tiebreak, but Roddick fought back to capture the stanza.

Two games later, the ninth-seeded Berdych called it quits due to an apparent breathing problem at Ashe Stadium. Roddick's second-round opponent, Argentine Jose Acasuso, also retired against the American.

"I'll probably head out to the practice courts right now," said a fresh Roddick after his brief match.

Berdych is now 0-9 lifetime against top-10 players at Grand Slam events.

The 25-year-old Roddick will meet Monday's Roger Federer-Feliciano Lopez winner in the quarterfinals. The reigning three-time U.S. Open champion Federer beat the 2003 titlist Roddick in last year's final.

Roddick is seeking a trip to his fifth Grand Slam final (1-3). He also lost to Federer in back-to-back Wimbledon title bouts in 2004 and 2005.

A 10th-seeded Haas snuck past No. 6 Blake 4-6, 6-4, 3-6, 6-0, 7-6 (7-4). Blake has won only one five-set match in his career, and that came against Frenchman Fabrice Santoro on Thursday night.

Haas trailed two-sets-to-one before he rallied in the fourth. The German pocketed the set at love and ran out to a 2-0 lead in the fifth for an eight- game winning streak.

But Blake bounced back and had three match points while leading 5-4 in the fifth, only to see Haas fire three big serves to stave off elimination.

The bout was then decided by a fifth-set tiebreak, which Haas won on an ace on his second match point of the day.

Haas, an Aussie Open semifinalist back in January, will appear in his third U.S. Open quarterfinal. He also reached the quarters here a year ago and has advanced to the round of eight here in three of the past four years.

Blake was seeking a trip to a third straight U.S. Open quarterfinal, but Haas thwarted his efforts in 3 hours, 17 minutes.

Both Haas and Blake fired 18 aces apiece, while the German tallied 69 winners and 39 unforced errors and Blake recorded 75 winners and 38 errors in the brilliant match. Haas also broke Blake's serve seven times, compared to six breaks for the American.

Haas awaits the winner between Nikolay Davydenko and Hyung-Taik Lee.