Japan's Kohei Uchimura failed to win his 11th straight national championship on Sunday, finishing third behind teenager Kakeru Tanigawa.
Uchimura, the two-time Olympic individual all-around gold medalist, scored 171.664 at Tokyo Metropolitan Gymnasium, while Tanigawa scored 172.496 to win his maiden title. Kenzo Shirai, the world champion in the floor and vault, was runner-up at 172.164.
At 19 years and two months, Tanigawa became Japan's youngest national champion. Naoya Tsukahara, a member of Japan's gold-winning team at the 2004 Athens Olympics, was previously the youngest, claiming the crown in 1996 when he was 19 years and four months.
"I still can't believe it. Uchimura-san had been Japan's top gymnast and I've respected him so I didn't think I can beat him," Tanigawa said. "I tried to pull off all of my routines as I usually do without giving them much thought, and the score just followed."
Uchimura's third place was a shock since he had topped the podium in every individual all-around event in Japan for nearly a decade. His last loss was in September 2008, when he was second in the national intercollegiate championships.
"This gives me a sample of something I haven't tasted up to this point," Uchimura said. "From now on, it's no longer about results."
Uchimura suffered an ankle injury at last October's artistic gymnastics world championships in Montreal and did not return to competition until March.
"Win or lose, either way is fine," said Uchimura, who said the pressure of his championship streak had put him in hell and his physical strength was at its limit on Sunday.
"I didn't make it to the finals at the world championships because I got hurt. But now (with this loss) I'm finally released."
The scores of the qualifying round and final are combined to determine the winner of the competition, which double as a qualifier for the world championships that begin in October in Doha.
Uchimura topped the six-routine final by edging Tanigawa by 0.101 point. However, it was not enough to make up for his fifth-place finish in Friday's qualifiers.
Earlier in the day, Mai Murakami claimed her third straight women's championship. Murakami, the floor exercise world champion, totaled 112.398 points. Asuka Teramoto was second and Hitomi Hatakeda third.