Mike Ashley's Sports Direct has won a court injunction against Rangers disclosing confidential information about its retail deal with the club.
It prevents Rangers revealing details of their contract to an extraordinary meeting of the Championship club called by Ashley and being held on Friday.
The Newcastle United owner and Rangers shareholder asked for the EGM to force the club to pay back a £5m loan.
Sports Direct was also awarded costs of £20,000 at the Royal Courts of Justice.
The company complained that information had already been leaked to the media and asked the Chancery Division of the High Court in London for its deal with Rangers to remain private.
The application heard evidence from lawyers representing both sides but found in Sports Direct's favour and ordered Rangers to pay legal costs.
A judge ruled: "I am satisfied there is a real risk of disclosure tomorrow of confidential information."
Ashley had sent his lawyers to court after the Daily Record newspaper carried reports of what the judge was told was secret information relating to commercial links between Sports Direct and Rangers.
It was claimed in court that this information must have come from board members, but Rangers' lawyers said there was no evidence as to the actual source of the leaks.
Sports Direct currently controls around 75% of Rangers' retail operations, but the club say they want to challenge those contracts at the EGM.
The club have also asked shareholders to vote against resolutions put forward by Ashley's company, which wants Rangers to repay a £5m loan and explain the decisions that led to the club being delisted from the AIM stock exchange.
Ashley said on Wednesday that repaying the loan would allow Rangers to restore some of their retail income.