We did this once in high school in the playoffs, started on the 18 and 16 plays later we scored, even ran the same exact play 6 times in a row. A ref who said he'd worked 20 years said he'd never seen anything like it.
This is not something we should be underrating, you could have a 5A against a 1A school and not pull this off, even if its just a scrimmage, we should be proud of this one in this day and age. Breaking a 90 yard or 20 yard run is one thing, but solidly getting 8-12 yards a run... that's not easy.