Sumo's big guns all opened with wins on Sunday, the first day of the 15-day Summer Grand Sumo Tournament.

Kakuryu, looking to win back-to-back championships for the first time in his career, earned an easy win against popular komusubi Endo at Tokyo's Ryogoku Kokugikan. Fellow yokozuna Hakuho also opened with a win, as did ozeki Goeido and both sekiwake wrestlers.

In the day's final bout, Endo, wrestling in one of the sport's elite ranks for the first time in his career, came in very low against the Mongolian yokozuna, who held his ground and eventually yanked the komusubi off balance and down to the sandy surface.

Hakuho, returning after sitting out the entire spring tourney with a toe injury, won a fierce confrontation with top-ranked maegashira Tamawashi. After Tamawashi repulsed Hakuho's charge with some nasty shoves to his throat, the two Mongolians gave each other menacing looks from a distance.

The follow through of his effort to throw off the yokozuna, however, left Tamawashi with his back to the straw, as the two stared each other down. Hakuho, looking for his 41st career championship, ended the stalemate with a couple of well-timed lunges that finally propelled his compatriot from the ring.

"I got irritated and that was that," Tamawashi said. "It's no good getting irritated."

(Yokozuna Hakuho returned to the ring Sunday.)

Ozeki Goeido showed his skill in an easy opening win over No. 1 maegashira Kaisei. As the Brazilian steamrolled forward, the ozeki seized a left-handed belt hold. Goeido used that in concert with Kaisei's forward motion to get around his opponent and force him from the ring.

Georgian sekiwake Tochinoshin overpowered smaller and quicker No. 2 maegashira Shohozan. The maegashira, who favors a hit-and-run game, went for belt holds against the powerful sekiwake, who won his maiden championship in January.

But despite coming into the tournament with fitness issues, Tochinoshin was able to lift Shohozan off his feet and deposit him kicking and struggling on the wrong side of the straw.

"It's a shame because I did well to get inside against him," Shohozan said. "But his arms are so long and he is just so strong."

Mitakeumi, whose long run at sekiwake came to a halt in March, opened his account as a komusubi by shoving out No. 3 maegashira Daieisho.

Mongolian mountain Ichinojo, fighting as a sekiwake for the first time since July 2015, easily shoved out up-and-coming 24-year-old No. 2 maegashira Abi.