Match that is a dead-heat (3)
I believe the answer is:
tie
This clue is a double definition.
'match' is the first definition.
(tie can mean a sporting fixture)
'a dead-heat' is the second definition.
(I've seen this before)
'that is' acts as a link.
(Other definitions for tie that I've seen before include "Knot; link" , "A draw or male neckwear" , "hamper" , "Bond; draw" , "around the neck?" .)