A sumo champion pulled his weight during a drunken brawl smashing a beer bottle over a fellow wrestlers head, according to a report.

Grand champion Harumafuji, 33, apologized Tuesday for causing trouble, and sending a fellow Mongolian wrestler to the hospital with a fractured skull and concussion, after a boozy night last month, the BBC reported.

The victim, Takanoiwa, 27, announced Monday that he would not be taking part in the 15-day Grand Sumo Tournament, which began this weekend in western Japan, according to local public broadcaster NHK.

Sources at the Japan Sumo Association told the outlet the attack took place during a gathering of wrestlers from Mongolia on Oct. 26.

As for Takanoiwas injuries, I apologize deeply for causing trouble for stable master Takanohana, people affiliated with Takanohana stable, the Sumo Association and my stable master, the wrestler told local reporters Tuesday.

The Japan Sumo Association is investigating the incident and announced that Harumafuji would sit out the tournament.

Weighing in at 300 pounds, Harumafuji is considered a lightweight sumo wrestler, and is lauded for his technique in the ring.

The incident was reported to police but it was unclear if the champion would be charged.

The ancient sports traditional protocol calls for participants to live up to a strict standard of good behavior.

Fighters are even expected not to show emotion after victories so as not to be inconsiderate to the losers.