TOKYO (UPI) - Yokozunas Tochinishiki and Wakanohana won their bouts in convincing fashion Sunday on the opening day of the 15-day sumo tournament at the Kokugikan Arena here.
    But a major upset was registered when ozeki (champion) Kotogahama was humbled by a fifth-ranking maegashira, 34-year-old Shionishiki.
    Kotogahama made the mistake of taking the offensive when the five judges were about to give them "mizuiri" or a breathing spell. He tried to change his arm hold. Shionishiki was quick to take advantage of the slight relaxation in Kotogahama's defense and promptly pushed him out of the ring.
    Tochinishiki drove sixth-ranking maegashira Kitanonada out of the ring while Wakanohana stopped the charge of fifth-ranking maegashira Matsunobori and pushed him out.
    Two candidates for a vacant ozeki spot were defeated, Sekiwake Fusanishiki proved to be no match for the fast-charging Naruyama and was driven out in a matter of seconds.
    Tochihikari was on the verge of throwing the big Wakachichibu. But Waka saved himself and finally threw Tochi with an arm throw for an upset win.