Yokozuna Hakuho, who was seeking to extend his record championship haul to 41, pulled out of the ongoing Nagoya Grand Sumo Tournament on Wednesday due to a right knee injury.
Hakuho won his first three bouts in the 15-day meet at Dolphins Arena, but the 33-year-old Mongolian from the Miyagino stable was diagnosed with injuries to his patellar tendon and shin bone requiring two weeks of recovery period.
His withdrawal leaves Kakuryu as the only grand champion competing. Yokozuna Kisenosato withdrew prior to Sunday's opener.
Hakuho has withdrawn from three of four tournaments this year. He pulled out of the New Year meet in January on Day 5 after posting a 2-2 record and did not compete in the spring tourney in March.
Hakuho will concede Wednesday's match by default against No. 2 maegashira Chiyonokuni. The grand champion is looking to stay on track toward 1,000 top division wins.