Gamba Osaka made a stunning exit from the Emperor's Cup on Wednesday, losing 2-0 to Hosei University in the third round of the competition.
Ryotaro Onishi and Riku Morioka scored for Hosei in the 24th and 70th minutes, respectively, to secure the surprise win over the J. League first-division side at Ajinomoto Field Nishigaoka.
J1 leaders FC Tokyo also bowed out in an upset, losing 1-0 to second-division Ventforet Kofu.
In other results from the 16 matches played across Japan, Urawa Reds, the defending champions, advanced to the fourth round with a 2-1 victory over J2 club Mito HollyHock, while Yokohama F Marinos held on for a 2-1 derby win over second-division Yokohama FC.