Professor Lucas Lepri explains how to escape from an opponent's single leg attempt and counterattack with an arm triangle submission. First, Lucas immediately drives his arm between himself and the opponent when the opponent shoots for a single leg takedown. When the opponent lifts Lucas' leg off the mat, Lucas lowers his weight on the opponent's back, feeds his other hand behind the opponent's upper triceps, and locks his hands together. As the opponent attempts to finish the single leg takedown, Lucas sits and uses the leg that the opponent is attacking to bump and force him to roll. Lucas then tightens his hold by pushing the opponent's elbow downward with his free leg and pulling his hand across before he locks and squeezes for the arm triangle submission.