Beat that! Hurdler's run over bus, first of all (5)
I believe the answer is:
throb
'beat' is the definition.
(I know that throb is a type of beat)
'that hurdler's run over bus first of all' is the wordplay.
'first of all' indicates taking the first letters.
The first letters of 'that hurdler run over bus' is 'THROB'.
(Other definitions for throb that I've seen before include "Beat like heart" , "Sound of engines" , "Beat strongly" , "Pulsate with force" , "Palpitate, quiver (with emotion)" .)