A bitter rivalry between two Brazilian clups exploded in a wild-22 man brawl after provocative players decided to taunt their relegation-threatened foes by bearing mock coffins.
Known as the Gre-Nal, the match between Gremio and Inter is considered the country's fiercest 'classico'.
That is because there are only two top teams in Porto Alegre, compared to other cities, such as Sao Paulo and Rio de Janeiro, where there are at least four.
Gremio have had a rough time recently, causing Brazil global shame last weekend when footage spread of their fans trashing the VAR set-up and storming the pitch of their Gremio Arena following a 3-1 home loss to Copa Libertadores holders Palmeiras.
Some supporters were also captured fighting in the internal car park with police, with the club facing a 10-match home ban for the incident.
The club, which produced the likes of Ronaldinho and returned hero Douglas Costa, won South America's equivalent of the Champions League as recently as 2017, making their seven-point gap from escaping the Brasilieirao's relegation zone a shocking fall from grace.
Inter are faring far better in seventh, and relished the chance to pile on the misery for their sworn enemies.
That was afforded by ex-Shakhtar Donetsk and 2018 Brazil World Cup squad member Taison, who scored the only goal of the game in the 40th minute.
Matters got out of hand at full-time when midfielder Patrick Nascimento took a mock coffin painted in Gremio's blue and black colors from members of the crowd and paraded it on pitch.
One of Inter's substitutes also joined in as they headed towards one of the stands of the Beira-Rio stadium to celebrate with fans, but the scenes understandably irritated Gremio players including left-back Bruno Cortez, who went for opposition players while a 22-man brawl broke out.
Gremio's Thiago Santos and Vanderson were also heavily involved, with Nascimento and Cortez shown red cards after the final whistle.
The trouble took around 15 minutes to defuse, with security helpless until police stormed the pitch.
Chants of "Serie B" – the second tier Gremio are destined for – rang out around the 50,000-capacity ground, while the coffins also contained a letter 'B'.
In an interview, Gremio coach Vagner Mancini called the confusion "regrettable". "Football is to be played on the field," he insisted.
"I had already entered the locker room, then I ended up returning [to the pitch].
"When I saw the confusion, I didn't understand [it], [but] then I heard some of the things that had already happened.
"The most important thing is for us to look at the football side [of things], [because] these scenes are regrettable. We regret the attitude of many people," he added, emphasizing that he would not be making any further comment.
Gremio play eighth-placed Fluminense in midweek, when a win for them would benefit Inter's bid for continental competition qualification.
Also on rt.com ‘We’re getting smashed’: Fury issues ominous warning to Man United stars as hulk raises fist & tells them to ‘be prepared’ (VIDEO)