It was, by all accounts, a left hook that transformed Darryl Tyson from a fighter to a boxer almost 10 years ago.

But the punch was not his. Thrown by an opponent in the semifinals of a local Golden Gloves tournament in 1977, the blow slammed into the side of Tyson's head and left him dazed and disoriented. It was easily the hardest he had ever been hit.

"I couldn't see anything but darkness," Tyson, now 25, remembers. "I went into that fight feeling like I couldn't be beat. But he hit me good. He hurt me. My first reaction was like, 'Man, I'm going to hit you back and hurt you,' and I ended up losing. But later I decided I had better dedicate myself to the sport if I was going to make it as a boxer.

"I know better now. I know how to run and counter-punch and make the other guy show me what he's got. If someone hit me like that now, I'd just play it off."

Such is the confidence with which Tyson (23-1) will defend his World Boxing Council Continental Americas lightweight championship against veteran Freddie Roach (40-10) of Las Vegas in a 12-round feature bout Saturday at the D.C. Convention Center. The four undercard bouts, featuring local lightweights Jose Ortez and Jocko King and welterweight Darryl Lattimore, will begin at 7:30.

Currently ranked the No. 1 contender for the world lightweight title by the International Boxing Federation (IBF), Tyson knows that a win over Roach will likely earn him another match against IBF champion Jimmy Paul. Tyson handed Paul the only loss of his career more than two years ago with a 12-round split decision in Atlantic City, and went on to capture the WBC Continental Americas championship last July with a decision over Melvin Paul (no relation) in Atlantic City.

So far, Jimmy Paul, WBC champion Hector Camacho and World Boxing Association champion Livingstone Bramble have been unwilling to give Tyson a title fight.

"There's a lot of fighters ducking Darryl right now," said his manager, Norman Smith.

But all of that seemed very far away as Tyson sat on a folding chair in the tiny House of Champions gym in Northeast Washington one day this past week and talked quietly about his mother, his six nieces and his sister, Cynthia, who died four years ago of cancer. Friends speak of a special bond between Tyson and Cynthia, who would take him in at all hours, cook for him and tell him how he would be somebody someday.

Tyson travels to North Carolina at least once a year to visit her grave.

"Her spirit is always with me," said Tyson. "My whole career is dedicated to her. She called me the champ even when I wasn't the champ."

Although Tyson has lived in a small room above the gym for the past three years, he remains extremely close to the 13 other members of his family living in a house on N Street. What money Tyson has earned in the ring has gone to support his relatives, all of whom regularly attend his matches, and it is clear any future purses are similarly earmaked.

Although a two-sport star at Dunbar High School, Tyson's size (5 feet 7, 135 pounds) and mediocre grades precluded any hopes of a traditional college or professional career. Moody and withdrawn, he earned a reputation as a troublemaker by beating up a 6-1 student during a gym class basketball game.

"I was so frustrated in school," Tyson said. "I didn't know what I wanted to do with my life -- I just wanted to graduate." Once out of school, he began to take boxing more seriously. "Since I used to get into so many fights and arguments, anyway, I decided I'd rather do something with my hands that was constructive rather than just banging them up on people."

Enter Robert (Pappy) Gault, the former U.S. Olympic boxing coach who runs the House of Champions, a folksy little gym with fading fight posters on the walls and cats and dogs underfoot. Although initially unimpressed with Tyson's attitude, Gault gradually began to see a quick, powerful and highly intelligent fighter emerge.

Tyson turned pro in 1982, winning his first five fights before losing to David Grayton on a controversial, eight-round decision Jan. 22, 1983. Since then, the man they call "The Terrible T" has had 18 straight wins (seven by knockout).

"Darryl has the willpower and desire to accomplish something in life now," said Gault. "We're going to win all three championships."

Which one first?

"Whichever one we can get."