Thanks for the kind words everyone. This was from only the second roll through an unfamiliar new camera, so a bit of luck was also involved.
pentaxuser, not really panning in that the camera was handheld steady at a pre-focused location and the action was allowed to move into and across that steady frame during the 1/4 second exposure. Then the on-camera flash was manually triggered when the subject was centered. The camera was about ten feet from the subject. I made eight attempts total and this one was the best.