Kagiyama was the final competitor on an evening of outstanding skates at the Four Continents and put forth a dynamic combination of power and presentation.
Both champions won by wide margins over the second-place finishers.
American Vincent Zhou and Japanese teenager Mana Kawabe are both in second place heading into the free skate.
“Everything is improving now and technically spiritual,” Uno said. “The most important thing I have practiced is the quadruple salchow.”