Gain Ground: Tank VS Tornado

When Gain Ground was remade for the Sega Genesis, a new world was added that wasn't in the arcade version. The new world's final boss was a tank, which drove around the screen and fired wide spreads of bullets. However, a well-timed tornado can bounce around the inside of the tank's hitbox, eliminating in milliseconds what is usually a massive challenge to defeat without casualties. This trick actually works on all of the bosses- the tank is just the easiest and most useful case for players to abuse.
Video Source: https://www.youtube.com/watch?v=8ArE0utf9rg

Example of:
Outside-the-Box Tactic