NEW YORK -- After Andy Roddick's first-round thrashing of wild-card Scoville Jenkins -- he lost only four games, his best effort ever here in 20 matches at the Open -- Roddick was asked about the comments complimentary of his massive serve made by Rafael Nadal, his second-round opponent.

"I think Rafael is being humble," Roddick said Tuesday. "Personally, I think he's a lot more confident in his abilities than he's letting on if he said he didn't have a clue. He's got more of a clue than any 18-year-old I've seen."

Rafael Nadal of the Mallorca region in Spain could, in fact, be the next Andy Roddick, or at least something close. Their styles differ, but they both have big-time games. Nadal, 18, is a powerful 6-foot, 165-pound left-hander with all the shots. More important, he is "a very good fighter," according to his friend and mentor Carlos Moya.

But at this stage, anyway, Nadal turned out to be right, while Moya was wrong. On Friday night, Nadal was generally clueless against the U.S. Open defending champion, who won 6-0, 6-3, 6-4 and advanced to a third-round match against Guillermo Canas. The match required a tidy 97 minutes.

Nadal played hard to the end, leading 4-2 in the third set before losing the last four games.

"He's a fiery guy," Roddick said. "If he'd a won that third set his emotions would have been running high, and who knows what would have happened? He competes. He wants to win every match, every time. I see a lot of good things there."

When Nadal was asked a question about Roddick's serve, he shook his head.

"Serve was not the difference," said Nadal, who complained of a sore right arm. "I think I don't play my best tennis today. If I don't play very good, I can't win."

To understand Nadal's potential, here is some context:

Roddick, the No. 2 player in the world, turned professional when he was 18 years old. He finished that 2000 season as the world's No. 1 junior and had a string of impressive victories, including boys' titles at the Australian Open and the U.S. Open. Strictly, amateur, understand.

Nadal turned professional when he was 15 years old, a mere child.

And now, a seasoned veteran at the age of 18 years and three months, Nadal has already produced a distinguished professional resume: a victory last month in Sopot, Poland, seven other quarterfinals-or-better efforts, a 41-24 career record on the ATP circuit and a sporty 6-3 mark in the four Grand Slams in which he's appeared.

Nadal is ranked No. 49 among ATP players -- there is no one younger ranked higher. This despite a stress fracture in his left ankle that kept him out for nearly three months. He has been hitting balls with the best Spanish players for years, so there's no fear factor when he faces marquee players. Before the Roddick match, he was 3-2 against players ranked in the top 10.

Back in March, Nadal met No. 1-ranked Roger Federer in the third round at Miami's Tennis Masters Series event and flogged him, 6-3, 6-3. His summer hardcourt season, however, has been brief. He lost his first-round matches in Montreal and Cincinnati -- albeit, to Lleyton Hewitt and Juan Ignacio Chela -- then flew back to Poland to win five matches and his first professional title in Sopot. Maybe next year he should play a few more hardcourt matches coming into the Open.

Roddick, who turned 22 on Monday, was physically dominant. There were times when Nadal seemed intimidated.

The first serve from Roddick was a 142 mile-an-hour ace. The second was a 152 mile-an-hour ace that tied the U.S. Open record he set in the first round. Serving in the second set, Roddick hit a serve that glanced off Nadal's racket and hit him in the mouth. Two games later, Nadal couldn't get out of the way of a 143 mile-an-hour serve into the body and took a shot in the shoulder, which knocked him down.

After winning 12 of the first 15 games, Roddick briefly lost his concentration and was broken in the first game of the third set. A weird moment at 0-2 seemed to bring him back. A Roddick forehand had so much torque it wrenched a ball from his pocket. The umpire's correct let call cost Roddick a point, but it seemed to fire him up.

Roddick leveled the set at 4-all and finished in a blur, breaking Nadal in the final game -- at one, point, Roddick hit a between-the-legs shot when a routine forehand would have served nicely.

He seemed intent on tormenting Nadal throughout the match. He taunted him after he made a nice volley -- "Ha, ha!" -- and glowered constantly. Nadal, fist-pumping at various junctures, scowled right back. It was the first match between them but, almost certainly, not the last. Maybe Roddick senses a future rivalry and was trying to establish a beachhead.

The tournament is setting up nicely for Roddick. Three formidable seeds in his half of the draw fell to underdogs in second-round action. No. 7 seed Juan Carlos Ferrero, a finalist here a year ago, lost to Stefan Koubek. No. 8 seed David Nalbandian, who held a match point against Roddick in last year's dramatic semifinal match, lost a five-set match to Mikhail Youzhny. No. 12 Sebastien Grosjean fell to Tommy Haas. If Roddick keeps winning, he'd meet No. 4 seed Lleyton Hewitt in the semifinals and No. 1 Roger Federer would be the likely opponent in the finals.

Is he as unbeatable as he looks right now? Roddick laughed when the question was lobbed his way in the post-match press conference.

"I don't know," he said. "I've never felt unbeatable, for sure."

Not yet, anyway. Check back in a week's time.

Greg Garber is a senior writer for ESPN.com.