SYDNEY, Australia (AP) _ Jose Navarro boxed his way into the Olympic flyweight quarterfinals, and this time his father saw it.

With his father and older brother Carlos Jr., cheering him on, the 19-year-old Navarro scored half of his 12 points in the fourth round for a 12-9 decision over Hicham Mesbahi of Morocco at 112 pounds Sunday afternoon (Monday EDT).

When the decision was announced, Mesbahi threw up his hands, fell to his knees and pounded the canvas. There were boos.

Navarro's father had missed his son's opening-round win because he missed a plane in Los Angeles.

Dad almost saw his son eliminated.

After building a 5-2 lead in the second round, Navarro had trouble solving Mesbahi's defense and he trailed 7-6 after three rounds.

After the third round, Navarro said he looked at his father and "My dad put his hands up and said in Spanish, `This is it."'

Navarro became the sixth U.S. boxer to advance to the quarterfinals. He will box Jerome Thomas of France on Wednesday afternoon.

Soon after Navarro's win, Ricardo Williams Jr. of Cincinnati became quarterfinalist No. 7.

The 19-year-old Williams, boxing with a picture of his 7-month-old son taped to his left boxing boot, stoppd Olusegun Ajose of Nigeria on the 15-point rule (21-6) at 139 pounds. It was the second 15-point-rule victory for Williams.

Olanda Anderson, an Army sergeant stationed at Fort Carson, Colo., was to box at 178 pounds later in the afternoon.

"I knew I was behind by one point in the last round and I had no choice but to go out there and just throw," Navarro said. "I knew I had to step it up a lot. It's just an experience for me. I'm going to learn a lot from this fight, as I do from every fight."

In the 139-pound bout, Ajose drew applause when he did a little showboating, but it was Williams who had the fun.

"You're supposed to have fun, it's a sport," Williams said.

Ajose got the crowd on his side in the fourth round when he scored three points to cut Williams lead to 16-6. The left-handed Williams then unleashed five scoring blows to the head and ended the fight with 40 seconds left.

"It gets more exciting as it goes on," said Williams, who will box Alexandre Leonov of Russian on Wednesday afternoon.

Two of three Americans who boxed Saturday night advanced.

Rocky Juarez, the 125-pound world champion from Houston, outpointed Falk Huste of Germany 17-15 and set up a quarterfinal showdown on Wednesday against Somluck Kamsing of Thailand, the 1996 Olympic gold medalist. Kamsing beat Tulkunbay Turgunov of Ubekistan 6-2.

Jermain Taylor of Little Rock, Ark., pounded out a 23-9 decision over Scott McIntosh of Canada at 156 pounds.

Then super heavyweight Calvin Brock of Charlotte, N.C., became the fourth U.S. boxer to lose. He took a standing 8-count, was knocked down and stopped in the fourth round on the 15-point rule (21-5) by Paolo Vidoz of Italy, a bronze medalist at the 1999 world championships.

The 20-year-old Juarez, who beat Huste 12-6 in the quarterfinals at the world championships last year in Houston, clinched his victory this time with a scoring blow late in the fourth round for a 17-14 lead.

Four times during the fast-paced four rounds Juarez led by three points, but never for very long. Each boxer got a couple of points for body blows. In some bouts judges have ignored punches to the body.

The 22-year-old Taylor clinched his match against McIntosh by outscoring the Canadian 11-3 in the third round. He will box Adnan Catic of Germany in the quarterfinals on Wednesday.

Brock was simply outclassed in the last two rounds. After a 2-2 first round, Brock fell behind 6-3 after two rounds. Then he took a battering in the third round when he took a standing 8-count, and he was knocked down with a body punch in the fourth. The fight was stopped in the closing seconds.

(Copyright 2000 by The Associated Press. All Rights Reserved.)