As Treat Huey slid around the soft gray-green clay at Rockville's Woodmont Country Club yesterday, it seemed as if any shot he hit touched down just inside the lines.

With perfect drop shot after perfect drop shot, the top-seeded Huey needed just one hour to dispatch Marek Czerwinski, 6-1, 6-1, in the semifinals of the weeklong USTA boys' 18 National Clay Court Championships, which have been played at five Washington area tennis clubs.

"At the end I think he knew I was playing too well," Huey said. "He wasn't so much frustrated as he knew inevitably he was about to lose."

Huey, of Alexandria, had no trouble with a nervous-looking Czerwinski, who had already knocked out No. 4 seed Michael Samara in the round of 32. It looked almost too simple for Huey, as he seemed to coast through both sets, not extending more energy than was necessary.

"It was a lot easier than my last couple matches," Huey said. "I was hitting the ball real well. From that, everything else was going right. . . . I wouldn't say he's the best on clay. He's a lot better on hard court."

Huey, the top-ranked boys' 18s player nationally, will face second semifinal winner and No. 2 seed Daniel Yoo in today's final. Yoo outlasted fellow Floridian Jean Yves Aubone, 5-7, 6-4, 6-0.

Exhausted and physically drained, Yoo said he was looking forward to a better match against Huey, who watched Yoo's semifinal from a seat off to the side of the court.

"I couldn't give him [anything] because he's going to come back," Yoo said. "I had to focus until the last point."

In a back-and-forth first set, Yoo and Aubone managed to break each other's serve in seven of the 12 games.

After Yoo had gone up 5-3, Aubone took the next four games to win the first set.

But Yoo picked it up in the second, seeming to find his rhythm as he changed his strategy, focusing more on hitting balls high to Aubone's backhand.

Throughout the match, the players consistently argued calls in front of an umpire who occasionally had to be corrected after calling out the wrong scores.

"I just ran out of gas up a set and 4-5" in the second, Aubone said. "It was tough. Up a break in the second and ran out of gas and completely rolled over."

When Huey and Yoo meet in today's final at 12:30 p.m., a spot in the main draw of the Legg Mason Tennis Classic will be up for grabs. The winner of the boys' 18 singles gets a shot to face professional tennis stars such as Andre Agassi, Lleyton Hewitt and James Blake in the 32-player main draw. The singles' runner-up gets a wild card into the singles qualifier.

Huey also has a chance to make it into the Legg Mason with his doubles play. The boys' 16 and 18 doubles winners will be put on the short list for the singles qualifier at the Legg Mason.

Huey and partner Jason Pinsky, of Potomac, play in today's doubles semifinals as the top-seeded duo. Pinsky, the third seed in singles, was knocked out in the round of 32 by Aubone.

In the boys' 16 singles, Spencer Vegosen meets Sam Querrey in the finals today at 10:30 a.m. at Woodmont.

Vegosen beat Cory Parr, 6-7 (3-7), 7-5, 7-5, and Querrey won, 7-5, 6-1, over Mateusz Kecki. The boys' 16s winner also receives a wild card into the Legg Mason singles qualifier.