Forum:Smashing Ground vs. Face-Down Monster

Can Smashing Ground destroy a face-down defense position monster if that is the only monster on your opponent's side of the field. The effect of Smashing Ground and all IOC-EN are not specific enough to say it only affects face-up monsters. As an example, here's Smashing Ground's effect;

"Destroy 1 monster with the highest DEF on your opponent's side of the field."