The pair exchanged insults throughout the tie in Jeddah, sometimes in good spirit, other times not, with Vini Jr eventually challenging Simeone to "meet me" after the game.
"What happens on the field, ever since we were kids, stays there, nothing to comment on," stated Simeone afterwards.
The Argentine was asked about a cheeky dig at Vini which was picked up by touchline microphones. Simeone told the Brazilian at one stage: "Florentino (Perez, Real Madrid president) is going to get you fired, 'remember' what I'm telling you..."
"I don't remember, I have a bad memory," responded Simeone with a wry grin.
It all started when Atletico's bench jumped up after a shot from Julián Álvarez struck Real defender Toni Rúdiger's hand, protesting to the referee. It was then that Vinicius began his personal confrontation with members of the bench.
He approached the Atlético bench with an obviously mocking attitude: “Yeah, yeah, they’re going to call a penalty for you.”
Simeone, standing in the technical area, heard Vini's taunt and told him to keep playing and forget about the fans. At this point, far from calming down, the Brazilian turned to the Argentine with a smile and the same attitude: “Don’t worry, they’ll call a penalty for you now."
That comment led Simone to making his warning about what would happen to him with Florentino Pérez.
But beyond the good-natured back-and-forth, the provocative attitude of Vini and the air of contempt with which he addressed his staff saw Simeone confront Real captain Dani Carvajal at halftime, before heading down the tunnel.
Pointing to the touchline, Simeone appeared to tell Carvajal the reason for their clash.
In the 81st minute, Vinicius Jr was substituted by Xabi Alonso, and the feud reignited. Simeone again confronted the Real Madrid player, and Vini challenged him to a meeting after the match - something which Simeone happily agreed to.