The bombshell dropped before the day's action in the elite makuuchi division even got started at the New Year Grand Sumo Tournament on Wednesday.
Yokozuna Hakuho and Asashoryu improved to 4-0 to remain in a share of the lead with rank-and-filers Kakizoe and Kisenosato in the early going, but it was Chiyotaikai's announcement of his retirement that was the story of the day at Ryogoku Kokugikan.
Chiyotaikai called time on his career with little hope of getting the 10 wins needed to regain promotion to sumo's second-highest rank of ozeki.
The battle-fatigued 33-year-old forfeited his bout with Estonian Baruto the same day, ending his campaign with an 0-4 record with 11 rest days.
"I gave myself an ultimatum, so I don't have any regrets. I just don't have the power to continue wrestling my brand of sumo anymore," said Chiyotaikai.
Back in the ring, Hakuho manhandled Goeido (1-3) in the day's penultimate bout, tackling the No.2 maegashira over the edge to extend his winning streak to 28 from last year's autumn meet.
Asashoryu, meanwhile, was all business against Miyabiyama (1-3), getting his left hand inside for a firm grip before sending the No. 2 maegashira flying into the ringside seats with a healthy shove.
But the ozeki wrestlers all fell like dominoes, with even warhorse Kaio being shown the exit a day after getting his record 808th victory.
Toyonoshima (1-3) stunned Harumafuji, sending the Mongolian ozeki to a first defeat with a dynamic underarm throw, while komusubi Kakuryu (2-2) dumped Kotooshu (3-1) with the same technique to also knock the Bulgarian ozeki out of share of the lead.
