Head of television succeeds when acquiring top US drama (4,5)

'us drama' is the definition.

'head of television succeeds when acquiring top' is the wordplay.
'head of' says to take the initial letters.
'succeeds' becomes 'wins'.
'when acquiring' means one lot of letters goes inside another.
'top' becomes 'peak' (I've seen this before**).
The first letter of 'television' is 't'.
'wins' going around 'peak' is 'winpeaks'.
't'+'winpeaks'='TWIN PEAKS'