TAMPA, Fla. -- World champion Ricardo Juarez led a parade of seven U.S. boxers into the Olympics with semifinal victories Thursday night at an Americas qualifying tournament.

The parade got off to a stumbling start when Brian Viloria, the world 106-pound champion from Waipahu, Hawaii, was outpointed 4-1 by Ivan Calderon of Puerto Rico, a New York City Golden Gloves champion in 1995-96.

Five judges scored the fight on paper because of computer failure. All the other bouts were scored by computer.

"There can't be any better feeling than, as of now, you're going to Sydney, Australia," Juarez, of Houston, said after battering Andres Ledesma of Colombia 17-3 at 125 pounds.

"I've been dreaming about it since I was a kid," said Juarez, who will turn 20 on April 15.

The first U.S. boxer to clinch a trip to the Olympics was Jose Navarro of Los Angeles, who edged Carlos Valcarcel of Puerto Rico 9-8 in a bout immediately following Viloria's loss.

"When Brian lost, that hyped me up," said Navarro, who outscored his opponent 6-3 in the third round. No scoring blows were recorded in the fourth round. "I though I scored two or three points in that round," the surprised Navarro said.

The other Americans earning trips to Sydney in September were Clarence Vinson, 119, of Washington, D.C.; Marshall Martinez, 132, of Fontana, Calif; Ricardo Williams, 139, of Cincinnati; Jermain Taylor, 156, of Little Rock, Ark., and Jeff Lacy, 165, of St. Petersburg, Fla.

Heavyweight Michael Bennett of Chicago, a world champion, and super heavyweight Calvin Brock of Charlotte, N.C., also won semifinals, but they also must win in Saturday's finals at Exposition Hall to qualify for the Olympics.

The 29-year-old Bennett, the oldest member of the U.S. team, hurt Mike Simmons of Canada with body punches and won 9-4.

Brock knocked down Victor Bisbal with a left hook in the fourth round and stopped him. Brock was leading 13-1 after three rounds.

Viloria and two other Americans beaten on Wednesday, Michael Simms Jr. of Sacramento, Calif., a world 178-pound champion, and Dante Craig, 147, of Cincinnati, can still qualify for the Olympics in tournaments April 17-22 at Mexico City or May 23-38 at Buenos Aires.

The International Amateur Boxing Association has allotted 66 Olympic spots to boxers from North, South and Central America and the Caribbean -- 22 from this tournament and another 22 in Mexico City (20 semifinal winners in 10 weight classes from 106 through 178 pounds plus the 201-pound and super heavyweight champions), 10 champions at 106 through 178 pounds at Buenos Aires and 12 automatic berths for Cuba, the world's No. 1 team.

"I should have gotten more aggressive," the 19-year-old Viloria said after his loss. "I can't take anything away from him. It was a real shock to me, but he boxed well."

"I was trying to outpunch him because he beat me before," said the 25-year-old Calderon, who used to live in New York's Bronx. Viloria beat him 9-5 in a dual meet last year.

Vinson took a standing 8-count in the third round, then knocked down Carlos Mesa of Colombia in the fourth round en route to a 15-6 victory at 119 pounds.

Martinez forced Patrick Lopez of Venezuela to take three standing 8-counts in scoring a 17-3 victory at 132.

Williams boxed his way to a 4-0 verdict over Michael Strange of Canada at 139 pounds. Williams registered single scoring blows against the taller Canadian in the second and fourth rounds and scored two points in the third.

Taylor beat Scott Macintosh 11-5 at 156 pounds, forcing the Canadian to take two standing 8-counts in the third round.

Lacy got off to a slow start in his 165-pound match. He took a standing 8-count in the second round and trailed 7-6 after two rounds to Jhim Rodriguez of Venezuela. Then he overwhelmed Rodriguez, forcing him to take two standing 8-counts in the fourth, and won 24-7.

Also qualifying for the Olympics were Troy Amos-Ross and Artur Binkowski of Canada.

The power-punching Amos-Ross outpointed Gusmir Perdomo of Venezuela 12-2 at 178 pounds and Binkowski stopped Juan Gonzalez of Costa Rica in the fourth round of a super heavyweight match.

Competing in the tournament that began Monday were 154 boxers from 23 countries in North, South and Central America and the Caribbean.