The whistle sounded, cheers erupted, corks popped and champagne flowed. The champions trotted off the field to collect their trophies and watched as their coach was doused with bubbly.

Celebrating is always in order for winners, but rarely is it sweeter than when you're 9 (or when you're a parent of a 9-year-old) and you've just won the championship in your age group in the prestigious Reston International Soccer Tournament. And that's exactly what the Reston Roadrunners did Sunday with a 4-0 victory over Braddock Road.

Soccer in the Washington area is at an awkward stage. The Diplomats closed down professional operations last week. At the youth level, however, soccer has never been stronger, as the fifth annual Reston tournament demonstrated.

The tournament, played Friday through Sunday, impressed even participants from other countries where playing soccer comes almost as naturally as breathing.

"I've never seen such enthusiasm," said Stephen O'Beirne, the 24-year-old coach of St. John Vianney's 19-and-under team from Ireland. "Our lads aren't used to playing three games in a week, much less three in two days. It's a bit hard on them."

O'Beirne and his "lads," who paid $500 each to travel to the tournament, had a rude introduction to American-style soccer. By the middle of the tournament, they had been thumped by teams from Reston and McLean after beating Annandale in their opening game.

If enthusiasm was the trademark of tournament play, organization was the key to its success. Among the logistical elements that had to be coordinated:

Scheduling of more than 250 games for 123 teams in 10 age groups.

Housing for teams from nine states, Canada, Peru and Ireland.

Keeping play moving on 21 Northern Virginia fields.

Giving two dances -- one for adults and one for teen-agers -- at a local hotel.

Staffing concession stands and emergency vehicles and assigning referees and tournament officials to each game site.

Ordering about 500 trophies for the first- and second-place winners in each division.

The weather, of course, was everyone's concern.

Fields were dotted with puddles on Friday, and balls splashed into them, sending a chilly spray over anyone nearby. Once, after giving up a breakaway goal, a Fairfax player stomped his foot in disgust, only to have it sink into several inches of mud.

The coach of a team from New Rochelle, N.Y., his voice reduced to a croak by the dampness and shouting, had to whisper to a parent nearby, who then shouted his instructions onto the field.

Another out-of-town coach was so disgusted with field conditions he bought straw and carried it onto the field to fill in the mudholes.

But soccer goes on in all weather, and sometimes the excitement grew remarkably intense, both on and off the field.

One 11-year-old player's mother yelled to him, "You're not fighting for the ball!"

"I wasn't even close to it," the boy countered.

To which his father warned, "You get mad at the other team, not at your mother."

In a game between 16-year-olds of the German-American Soccer Club of New Jersey and the Reston Atoms, a player from the visiting team drove in to shoot and the goalkeeper charged out to stop him. They collided. The ball squibbed off to one side, and another New Jersey player kicked it into the goal. It was the winning goal, but the visiting player involved in the collision never got up from the ground. He had broken his leg.

"American teams aren't just playing kick-and-run anymore," said Joe Thiel, coach of the German-American Soccer Club. It's becoming much more of a passing game. But the level of coaching needs to be improved. I've played all my life, since I was a child in Germany. But some of the American coaches haven't played; they should take some courses in coaching."

Thiel called the tournament "well organized" and added, "We're very impressed."

O'Beirne and his Irish players appeared bemused by the festivities as they surveyed the party room where a dance was being held for tournament participants.

"Some of the parents here (in America) are too enthusiastic," O'Beirne said. "I can see them pushing their kids. I mean, they do a lot of shouting from the sidelines, don't they? The parents seem too hard on the kids when they see them play.

"But the Americans have picked up the skills quickly. They play a very leggy game, keeping the ball at their feet. We tend to shy away from using the head, but they're learning."

Austin Dunne, 19, an auto mechanic who played for the Irish and is eligible to be called by the Homefarm Club, a professional Irish team, said of McLean. "They could do very well in Ireland. They were big and skillful."

At that point O'Beirne, Dunne and the rest of the 300 or so people at the party quieted down to listen to the awarding of the door prize.

The prize? Two season tickets to next year's Washington Diplomats game.

"I'd rather see the high school championships in the spring," someone muttered, no doubt summing up the feelings of many youth soccer fans.

Tournament winners from Northern Virginia (boys and girls) included: 19 and under, McLean; 13 and under, Annandale; 12 and under, Reston; 11 and under, Braddock Road; 10 and under, Reston; 9 and under, Reston; 8 and under, Reston.

All-girls teams: 15 and under, Braddock Road; 13 and under, Vienna; 11 and under, Reston.