I had a player decide he REALLY wanted to play with fire!

Grenade Punch(Combat)

Prerequisites: Grenade Proficiency, base attack bonus +7
Move like a butterfly, sting like a bomb.

Benefit: When you make an unarmed melee attack, you can pull a grenade from an available location like drawing a weapon and stick it to the target of the melee attack on a hit. The target will not receive a reflex saving throw to avoid damage and effects, and it will the the only target dealt damage and effects of the grenade.

Thoughts?