Rapid Grappler

Combat

You are a quick hand at grappling.

Prerequisite: Dex 13, Greater Grapple, Improved Grapple, Improved Unarmed Strike, base attack bonus +9 or monk level 9th. ® ™ 538 60 538 6

Benefit: Whenever you use Greater Grapple to successfully maintain a grapple as a move action, you can then spend a swift action to make a grapple combat maneuver check.

Source: Ultimate Combat