Bolt the door to catch the thief
Against an invasion which is too deep, play a capping move or a move to increase your moyo, then rely on your thickness. The opponent's lone stone must now fight for life surrounded by your thickness. It should be easy to prevent him from getting two eyes. Example:
The thief, quite simply, is the invading black stone at 1. Bolting the door means: close off his avenue of escape. If 2 doesn't seem like bolting the door to you, consider a capping play around a or even b. At c might work.
Also see Take away the fire from under the cauldron. These techniques are crucial to dealing with rogue invading stones in the most effective manner possible.