Lord Malcolm has upheld an appeal by Mr King, promising further legal wranglings between the pair.
G1 and the Mortimer family's Lynnet Leisure own neighbouring outlets on Royal Exchange Square, where even the location of their bins has led to complaints to the local authority.
The Mortimer family own properties including Club 29 and the
Rogano restaurant, while Mr King has The Social.
Matters came to a head three years ago with complaints that The Social's outside seating was infringing on access to Club 29, leading to Glenerrol, a Lynnet spin-off, and other property owners in the block drawing up a regulation limiting use of the "front common property".
An error by G1 in appealing the regulation led to it being thrown out and Mr King then taking the case to the Court of Session.
But in doing so, in addition to costing G1 an estimated £40,000-plus, it has made a largely anonymous legal process public.
A Lynnet Leisure spokesman said: "We normally don't complain about competitors and this should never have went as far as it has, but all efforts for an amicable solution were frustrated as the G1 Group refuse to discuss this matter civilly."
No-one from the G1 Group was available to comment.