In their first preseason game, the Dallas Cowboys didn’t get noteworthy performances from most of their defensive linemen. One of the few exceptions was free-agent signing Cedric Thornton. Signed from the Eagles 3-4, Thornton is expected to have a significant role for Dallas as a 1-tech. He certainly showed against the Rams why the Cowboys signed him.

The Cowboys defense presents a 4-3 under front with SAM linebacker Kyle Wilber lined up directly over the tight end. Note how Cedric Thornton (circled in yellow) has angled himself compared to his fellow lineman. By positioning himself this way, he’s indicating he plans to crash inside, expecting a run to the weak side (right) of the offensive formation.

This is the frame just after the snap. While the rest of the front four are at or behind the line of scrimmage, indicated by the black line, Thornton has surged into the A-gap with a lightning quick first step. He’s easily a full yard ahead of his teammates! The Rams center is clearly off to a poor start despite receiving help from the left guard, who is looking ahead at the linebackers in the second level.

Thornton blows past the center leaving him blocking air and forces the left guard to stay and block him to save the play. The rest of the left side of the Cowboys’ defensive line has done a good job of beating their initial blocks and have almost caught up to Thornton’s penetration.

Meanwhile weakside linebacker, Mark Nzeocha (circled in red), has gotten himself into trouble. In the first frame post-snap, Nzeocha is going forward but both he and Barry Church get caught watching the running back and take valuable steps towards the strong side of the formation. This allows the Rams’ right guard to place himself between Nzeocha and the ball, which will ultimately cost him precious seconds.

In the next frame, Thornton has completely blown past both of his initial blockers and has his eye on the true ball carrier, Tavon Austin (No. 11). David Irving is attempting to engage the fullback but is clearly lunging and off-balance. He may have beaten his original blocker but has lost containment of the edge.

If Irving had kept contain, he would’ve forced Austin to turn the ball up field into the waiting arms of Thornton for a huge loss. Instead, Austin has a clear angle to the sideline. Nzeocha and Church are forced into a foot race to keep contain. Nzeocha has beaten his man but is clearly not at full speed while the speedy Austin is ready to turn the corner.

David Irving has completely lost his balance and has taken himself out of the play. Without contain to slow him down, Austin is too fast for Thornton and has already beaten him around the edge. Nzeocha is now the Dallas’ best hope to stop Austin behind the line of scrimmage.

Unfortunately, Nzeocha underestimates Austin’s speed and takes a poor angle to catch the receiver. He does get close enough to make a diving attempt at Austin’s feet and trips him up just enough for Hitchens and Church to prevent the Rams’ receiver from getting the first down. However, this play should have ended in Los Angeles’ backfield for a significant loss.

Though his teammates didn’t capitalize on his penetration, Thornton showed exactly how he can be a disruptive force against the run. He displayed his quickness multiple times against the Rams usually being the first lineman off the ball. Thornton has a devastatingly quick first step and the savvy to diagnose plays before the snap. The veteran 1-technique is a huge improvement over former Cowboy starter Nick Hayden.

Pair him with the starting defensive and players like Sean Lee will be able to capitalize on Thornton’s disruptive abilities. The Cowboys have acquired an effective run defender and his presence will prevent opposing offenses from running roughshod through Dallas’ interior as they did many times in 2015.