Navy scored nine touchdowns and three field goals, while posting a shutout to win 72-0.
Winner of Navy-Penn will play winner of Army-Cornell in the inaugural Championship game.
Seven different Midshipmen scored touchdowns in the game.
Navy is 6-0 all-time against Post, outscoring the Eagles, 228-47.
Midshipmen unable to overcome slow start and fall to Black Knights in West Point.