last 2 clues. 5 down Set pieces from a flat football match(4,5)?e?? ?a?l? 11 across Rapid eye movement as discovered initially to reveal them. 6 ??e?m?
dead ball is a term used in football (you can google it for a full explanation). In this case I guess flat means dead and pieces mean balls..that's the best I can do for this early in the day !