and still encompassed far fewer games and hours than his historic first-round match at Wimbledon.

The 18th-seeded American lost to No. 12 Mikhail Youzhny of Russia 6-4, 6-7 (7), 7-6 (5), 6-4 Sunday night, then said he didn't think he paid any price physically at Flushing Meadows for all the wear-and-tear his body took at the All England Club during the longest match in tennis history.

"I don't think tonight had anything to do with that match, I would say," Isner said.

At Wimbledon in June, he won a 70-68 fifth set over Nicolas Mahut in a match that went a total of 183 games and 11 hours, 5 minutes spread over three days. In three full matches in New York — two victories and a loss — Isner played a total of 116 games, and a combined 8 hours, 12 minutes.

What Isner did concede might have hampered him was injuring his right ankle last month during a hard-court tournament in Cincinnati.

"I'm not the fastest guy out there, but I didn't feel as explosive. My legs I think just didn't have the bend that I needed to on my serve, on my groundstrokes," he said. "I mean, I wasn't dealt the greatest hand coming into this tournament with really no preparation. So that maybe had something to do with it."

The 6-foot-9 Isner lost Sunday despite pounding 33 aces at up to 144 mph.

"Of course, you understand (there) will be aces," Youzhny said of facing Isner. "But (here's the) main point: If you have some chances, try to take these chance, because (there) will not be too many chances."

Truly, Isner's biggest problem was this: 61 unforced errors, 25 more than Youzhny, who reached the fourth round at Flushing Meadows for the first time since he was a semifinalist in 2006.

Isner, never past the fourth round at a Grand Slam tournament, got broken four times — in the opening game of the match, twice in the second set, and once in the fourth.

"I was playing from behind pretty much a lot of that match," he said.

After trailing 5-1 in the second set, he made things interesting by breaking Youzhny for the only two times in the match to force a tiebreaker. Motioning between points to the Arthur Ashe Stadium crowd to make more noise, Isner steadily picked up support — and his level of play — and evened the match at a set apiece by converting his fifth set point on a service winner.

"You would think from there I would have all the momentum," Isner said. "He just keeps with it. That's a big credit to him. I mean, I definitely did have the momentum, but he just stayed steady and, you know, just outplayed me a little bit."

The third set also went to a tiebreaker, and Isner went ahead 4-3 with his 23rd ace, at 122 mph. But Youzhny collected four of the next five points, ending the set with the fourth of his five aces.

Youzhny will play 41st-ranked Tommy Robredo of Spain in the fourth round. Robredo's last two opponents retired during the matches, including Michael Llodra on Sunday.