Here's how Sherdog described it:
Jones doesn’t need to use any of his eight-inch reach advantage after all. Wessel comes straight forward swinging from the hip. After a wild exchange, Wessel tries to trip Jones, but ends up on bottom. Wessel quickly slips out and gets top position. But before he can mount any sort of offense, Jones snags Wessel’s arm and slaps on an armbar torqued by the most ridiculous amount of human pressure imaginable. Wessel screams through the submission.
The armlock actually reminds me of the one that Bibiano Fernandes uses, where you just pop the leg over the head rather than getting a full perpendicular hip rotation as you would in the "traditional" armlock from the guard. Definitely going belly-down helps to finish that kind of armlock. And that, combined with the sheer strength of Jones, made it a devastating finish.
