Professor Lucas Lepri shows how to pass the open guard by under hooking the leg. The opponent has the open guard and Lucas is standing. Lucas grips one pants and starts to move in. He places his knee on the opponent's leg that he initially gripped. His other hand is used to under hook the other leg and immediately grips the opposite side collar. Lucas stays tight. He now starts to move to the side by placing his knee on the opponent's torso. As he keeps moving, he replaces his knee with the other and posts out with the leg. The opponent now tries to push Lucas away, and Lucas just controls the position and transitions to side control.