Rangers have overturned a 12-month transfer embargo in the Scottish law courts - but they could now face more severe sanctions as a result.
The club succeeded in their application for a judicial review at the Court of Session in Edinburgh as Lord Glennie backed their assertion that a Scottish Football Association judicial panel had exceeded its powers in administering the ban on registering players.
The judge accepted the club's case that only the specific punishments laid down under the related rule should be imposed on the club for bringing the game into disrepute.
However, he proposed that the decision be referred back to an SFA appeal tribunal, which had upheld the decision that a transfer ban was appropriate punishment for a failure to pay more than £13million in tax last season.
The explicit punishments stated in the SFA's rule 66 are a maximum £100,000 fine, suspension or expulsion from participation in the game, ejection from the Scottish Cup or termination of membership.
The independent three-man SFA disciplinary panel had considered ending Rangers' membership, saying they viewed the offence second only to match-fixing in terms of seriousness, but decided a transfer ban was more appropriate.
Having already administered the maximum fine, an SFA appeal would therefore only be entitled to throw them out of the Scottish Cup for a spell or else stop the club playing football altogether in Scotland.
FIFA have also stepped in to the dispute, stating that they expect member associations to take "direct action" against clubs who take them to court.
The ruling brings fresh uncertainty to the club on the day administrators published a Company Voluntary Arrangement proposal.
Rangers are still subject to a Scottish Premier League transfer embargo but that will automatically be lifted if they come out of administration, which could happen as early as July 12.
Lord Glennie delivered his verdict on Tuesday afternoon after a three-hour hearing, which was continued from Friday.
A fellow Court of Session judge, Lord Carloway, had rejected Rangers' argument that the punishment was not open to the SFA when he chaired the appeal tribunal but the same QC, Richard Keen, was successful less than two weeks after that hearing.
Most of the argument centred around specific rules and how closely they should be interpreted. Section 95 of the SFA's articles of association, which state judicial panel members can administer any punishment they consider appropriate, were used to justify the embargo.
However, Lord Glennie felt article 94.1 was more appropriate given that it deals specifically with disrepute and states that it should be dealt with in terms of sanctions available in the judicial panel protocol, in other words the specific list of punishments for disrepute.
The judge also dismissed SFA QC Aidan O'Neill's assertion that the list offered a maximum punishment rather than an exclusive set.
Lord Glennie had earlier thrown out a challenge to the court's authority to rule, deciding the SFA had not been explicit enough in authorising the Court of Arbitration for Sport to settle disputes beyond their appeal stage in their rules, which underwent an overhaul last year.
Keen successfully pointed to Ashley Cole's failed attempt to appeal to CAS over his punishment for negotiating with Chelsea while at Arsenal in 2005, after which the FA tightened their rules.
Despite attempts by Rangers to suspend the additional sanction or at least revert the case back to the judicial panel, the judge proposed it return to the SFA appeal stage.
That leaves the club open to more severe sanctions, which they would struggle to overturn given that CAS has effectively been ruled invalid for Scottish disputes and that Lord Glennie admitted his only jurisdiction was whether the SFA applied their own rules properly and not their guilt.
An SFA spokesperson said on Tuesday: "We are surprised by today's verdict at the Court of Session, especially since the original sanction against Rangers FC was imposed by an independent panel chaired by a leading QC and upheld by an appellate tribunal chaired by a Supreme Court judge.
"We will now consider our position with our legal advisers before making any further comment."
A statement from FIFA read: "At the time of writing we have not received any communication from the Scottish FA.
"In such a case, FIFA will ask the member association to take action so that the club withdraws its request from the ordinary courts.
"FIFA will closely monitor the situation so that the issue is resolved as fast as possible."
FIFA's articles call for member associations to take "direct action" against clubs who seek redress before ordinary courts.
Rangers administrator Paul Clark said: "We welcome the decision by Judge Lord Glennie on Tuesday that vindicates the club's position that the original SFA judicial panel tribunal and the appellate tribunal acted beyond their powers in imposing a transfer embargo on the club.
"The costs for this legal action have been awarded against the SFA and it is our position it is very regrettable that court action was required.
"Both we, and the SFA, will have to study the full ramifications of the judgment when it is published and either side has 21 days in which to decide the next course of action or whether they wish to appeal."