The Young Nadeshiko were dominant throughout as Hanae Shibata, Hikaru Naomoto, Kumi Yokoyama and Yoko Tanaka put them into a comfortable lead, before Sofia Huerta struck a late consolation goal.
However the deadlock was broken just after the half hour mark, with Shibata capitalising on an almighty scramble in the Mexican penalty box after a poor clearance by Cecilia Santiago, with her resultant shot deflecting in.
Tanya Samarzich looked to draw things level with a shot from distance, but Sakiko Ikeda was equal to it leaving El Tri trailing at the break.
Samarzich had another effort soon after restart, but it took only 11 minutes of play to see their deficit widen. Naomoto was on hand to make it 2-0 with a fantastic right-footed effort from distance which Santiago couldn’t keep out.
The game was all-but put to bed by another long range strike, this time by a stunning Yokoyama effort into the top corner with 13 minutes remaining, to allow coach Hiroshi Yoshida and the home fans to relax.
“Our frame of mind in this tournament is that Japan is leading women’s football in the world,” said Japan coach Hiroshi Yoshida. “Solidarity is important, but I want to see more of a “look at me” attitude and for each player to improve individual techniques and skills and aspire to become a player at a higher level. If such individuals form a team and thrive to attain the same goal, the teamwork and the result should follow."