Saw the old boy hit the ball first (8)
I believe the answer is:
observed
'saw' is the definition.
(I've seen this before)
'old boy hit the ball first' is the wordplay.
'old boy' becomes 'OB' (abbreviation for a private school 'old boy').
'hit the ball first' becomes 'served' (I can't explain this - if you can you should believe this answer much more).
'ob'+'served'='OBSERVED'
'the' is the link.
Can you help me to learn more?
(Other definitions for observed that I've seen before include "Said" , "with witnesses" , "Ascertained by sight" , "Abided by, rules say" , "Kept an eye on" .)