stiff-arm 
verb [with object]
Tackle or fend off (a person) by extending an arm rigidly (illegal in rugby): he stiff-armed Jones...
- He nailed one in the jaw with the butt of his gun, but the other cop caught him behind the knees with his pistol, then spun around and stiff-armed him with his left arm.
- Mention his name and just try to imagine him doing something other than stiff-arming a tackler and high-stepping into the endzone.
- The baserunner, however, can counter this by stiff-arming his opponent or doing a rough slide into the base.