At least, that's what I call it. It is simple and brutal and gets everyone's attention.

Step one: Grab a hold of a downed opponent's ankle with both hands.

Step two: Take a step backwards with a diagonal slant. 

Step three: Yank! I want you to really think tug of war here. Don't forget to engage your back muscles for SPP (Superior Pulling Power). 

Step four: Drop your level while punching. Aim for the face or the abdomen. People are less likely to guard the abdomen. I personally aim for the leeeeever.

If you execute this properly when you yank them they will wind up beside you. At the apex of your yank, you want to spin them somewhat. This confuses their perceptions because they are being yanked and turned. You are essentially pulling them into your punch and out of position simultaneously. 

Variation: You can drop into a knee-on-belly position and fire from there if you want more security, or even drop into cross side, though in my experience it's easier to just let him have it and get it over with.