Sporting end relationship with rivals Benfica
Fans of both teams threw flares during Sunday's clash at Estadio Jose Alvalade, which finished 1-1 after Benfica forward Jardel cancelled out Jefferson's 87th-minute opener in the fourth minute of injury time.
However, it was a futsal derby at Benfica's Estadio da Luz that sparked the tension between the two clubs.
During that encounter, Benfica fans unfurled a banner that read "very light 96", a reference to the 1996 Taca de Portugal final in which a Sporting fan was stuck by a flare and killed.
Benfica supporters were also heard to chant "tomorrow there will be more" during the futsal game.
Sporting were angered that the Benfica directors present did not have the banner removed, with the situation made worse by the Primeira Liga champions describing the incident as "folklore".
The initial response of Sporting was to withdraw access to corporate hospitality for Sunday's game for Benfica directors Rui Costa and Nuno Gomes.
And Sporting have now taken further action by cutting ties with the league leaders.
A Sporting statement read: "In defence of basic human rights and the dignity of Sporting Clube de Portugal, we are faced with no other alternative than severing the institutional relationship with SLB and the presentation of this case with the competent authorities."
Sporting were fined €10,250 for irregularities in their security, while Benfica were handed a fine of €6,044 for the damaged to the away section of the Jose Alvalade.