Go over to the east to support Los Angeles in game (8)
I believe the answer is:
lacrosse
'in game' is the definition.
(I've seen this before)
'go over to the east to support los angeles' is the wordplay.
'go over' becomes 'cross' (to cross over).
'to the east' becomes 'E' (abbreviation).
'to support' is a charade indicator (letters next to each other) (in a down clue, some letters hold others up).
'los angeles' becomes 'LA' (abbreviation).
'cross'+'e'='crosse'
'crosse' put after 'la' is 'LACROSSE'.
(Other definitions for lacrosse that I've seen before include "Game played with nets on sticks" , "Game played with a netted stick" , "Like thirteen of the other clues in the French" , "Ball game using netted stick" , "Score's uncertain after the Spanish" .)