Party animal leaves headquarters with sports equipment (8,3)

'sports equipment' is the definition.
(baseball bat is a kind of sports equipment)

'party animal leaves headquarters' is the wordplay.
I cannot quite see how this works, but
'party' could be 'ball' (ball is a kind of party) and 'ball' is found in the answer.
'animal' could be 'bat' (bat is a kind of animal) and 'bat' is located in the answer.
'headquarters' could be 'base' (I've seen this before) and 'base' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

'with' acts as a link.

Can you help me to learn more?