Uppercut

From LSWiki

Usage: perform uppercut [at <target>]
Requirement to Use: martial arts skill of 20 or higher, brawling skill of 30 or higher, or unarmed combat skill of 60 or higher
   Typical Activity Cost: 20

Performs a close-range punch angled upward, delivering more power than an ordinary punch and potentially catching an opponent on the chin and knocking hir head backward -- when fighting an opponent with a head, of course. Moving you closer to your opponent as it does, performing this maneuver makes you a slightly easier target.