Debi Thomas landed all five triple jumps she attempted to win the women's title today, becoming the first black seniors champion at the National Figure Skating Championships.

Caryn Kadavy finished second and defending champion Tiffany Chin was third.

Brian Boitano, 22, of Sunnyvale, Calif., successfully defended his men's title, leading all the way and punctuating the victory with a fine freestyle routine that featured a triple axel, the only one completed in these championships.

Thomas, 18, of San Jose, skated her freestyle program with verve and, as she left the ice after her routine, pumped her arms in the air in a victory salute.

"This is like the pot of gold at the end of the rainbow," she said. "But it's at the end of a bumpy road instead.

"Oh, I can't believe it!"

Thomas should believe it. She led throughout this competition to culminate a sensational year in which she went from runner-up at the 1985 Nationals to victories at the National Sports Festival and two international meets.

"This is the most exhilarating feeling I've ever felt in my life," she said. "I thought winning at the Sports Fest was and I wondered how could I match it. Now I wonder how can I match this?"

But even after her scintillating freestyle routine, Thomas could not be certain she had won until Kadavy completed her program. Kadavy, skating next, landed three triple jumps but missed one and was not as spectacular as Thomas.

Thomas, who won the compulsory figures and was second to Kadavy in the short program, had 2.4 factor placements. Kadavy, 18, an Erie, Pa., native who trains in Colorado Springs, had 4.2.

Chin, 18, in her first competition since finishing third in the 1985 world championships, was third. Chin, a Toluca Lake, Calif., resident who trains in Denver, had been sidelined with a muscle imbalance and said earlier in the week that she was not in top shape.

After a conservative freestyle program, she totaled 5.4 factor placements.

"I had only eight weeks to prepare for this," said Chin. "It was jam-packed. I didn't have a lot of time to put my skating together."

Thomas, second to Chin last year, was placed No. 1 by six of the nine freestyle judges and earned another judge's No. 1 over Kadavy on a tie breaker.

All three women qualified for the Worlds in Geneva next month.

Thomas, a Stanford University freshman, said she "guessed it's a big accomplishment" to be the first skater of her race to win such a prestigious title.

"I never thought of that too much. I was just trying to be the national champion."

Boitano skated with a sore ankle, which he said was helped by acupuncture treatments. He was guaranteed a spot on the U.S. team for the Worlds by virtue of a third-place finish there last year. But he wanted to defend his crown.

He won the compulsory figures, short program and long program for 2.0 factor placements. In his long program, Boitano hit four triple jumps but failed to complete a fifth.

Scott Williams, 20, of Redondo Beach, Calif., was second with 6.6, and Daniel Doran, 18, of Denver -- with six triple jumps in his long program -- was third with 7.4.

Christopher Bowman, 18, of Van Nuys, Calif., who was second after two rounds, withdrew before the freestyle with a foot injury. However, the U.S. Figure Skating Association granted him an exemption and named him to the Worlds team instead of Doran.

Colette Huber of Los Angeles and Ron Kravette of Costa Mesa, Calif., won the junior dance. They had won the compulsory dance, optional set pattern and the free dance, giving them 2.0 factor placements.

In junior pairs, Kristi Yamaguchi and Rudy Galindo took the gold. Yamaguchi, of Fremont, Calif., and Galindo, of San Jose, performed side-by-side triple toe loops, the only skaters here to land side-by-side triples.