Move only one handle of control point tuck back completely inside anchor

Hi All, 
I see partial answers to this question online, but not a full answer. I'm sure it's been addressed before, but I cannot find the thread to save me. The ANCHOR POINT TOOL allows us to move one control handle at a time independently, I think I use to remember how to get one side, or one handle to tuck back into the anchor point, completely hidden in a snapping manner. Currently if I use the anchor point tool to move one handle point back into the little square I'm eye balling it back to 0,0 and I'm guessing there is a hot key or additional key to hold down with the anchor point tool to get it to quantize snap and hide completely inside the anchor point. Or maybe I'm going about this entirely in the wrong manner in the first place. Any suggetions? Thanks 

ATTACHED IMAGE: In the image below, as an example, I want to drag the shorter handle, tuck or retract it back fully into the little anchor point square, so it snaps fully out of sight.