It's funny how one poster can only fixate on a certain player in this play, however, the entire offensive line opened up holes and moved that DL backwards.
Notice the reach block that Smith has to accomplish in order to secure the cutback edge...
Martin helps Parnell and gets to the second level to get in the LB's lane...
Parnell destroys his man on the right side...
Leary helps Smith secure the edge by not allowing the defender to get across Smith before he secures him on the edge, and then cut blocks the LB at the second level.
That's just awesome to see!