Win a match using only miners, since miners do damage it's possible. Trust me.
Here's the rules:
- Win only using miners
- Use basic game principles
- Anything is allowed (spells, enchantments, upgrades, but on units: miners, enslaved miners is only allowed)
✓ Spells
✓ Enchantments
✓ Upgrades
✓ Units [Only allowed: Miners and enslaved miners]