In a historic moment for football, RB Leipzig and Red Bull Salzburg will go head to head in the Europa League on Thursday evening, despite both clubs being owned by the same company.
Austrian energy drinks giant Red Bull provides funding behind both of the teams, and will now see it's football offspring battle against each other on the European stage.
In what is a strange turn up for the books, Sportsmail takes a look at how this is possible and why the powers that be in football are allowing it to go ahead.
Timo Werner and Leipzig team-mates will be going up against Salzburg in the Europa League
UEFA has very detailed rules outlining that two teams with very close connections are unable to face each other within their competition.
The issue came to the fore during the 2017 season when both teams qualified for the Champions League, and thus immediately ran the risk of being drawn to compete.
A month-long investigation was launched by the football authorities, prompting both clubs to make serious behind-the-scenes changes in order to comply with rules and facilitate the progress of achieving joint European eligibility.
The two sides worked hard to prove to UEFA they were two separate entities, with personnel within the hierarchy stepping aside to focus solely on one club or the other.
Despite both clubs being funded by energy drinks giant Red Bull, they are allowed to meet
Following their investigation UEFA were satisfied the two clubs were not in breach of their regulations.
Prior to RB Leipzig achieving Champions League status following their incredible Bundesliga run of the 2016/17 season, the German side quickly went to UEFA with paperwork to show they were not in breach of article 5 of the organisation's rules - regarding the 'integrity of the competition.'
European football has strict defenses in operation to prevent two sides with 'common control' from meeting on the football pitch, particularly when the outcome could be influenced by an owner or owners' interest.
Red Bull Salzburg
On their findings UEFA determined 'significant and substantial changes' had occurred within the structures of RB Leipzig and RB Salzburg to show separation and fair grounds on which to compete.
UEFA accepted 'no individual or legal entity had anymore a decisive influence' and thus both sides were permitted into Champions League action. They would not meet in the competition, but now have been served up