Ireland fought back from a horror start to run in nine tries and beat Japan by 35 points in the first test of a two test series against Japan in Shizuoka.
The home side flew out of the blocks scoring two tries and kicking a penalty in the first 15 minutes to put Irish backs up against the wall right from the off.
Greg McWilliams side responded in impressive fashion, holding Japan to just a solitary try over the next 65 minutes, while scoring a sackful of their own.