Diego Simeone's side join Liverpool into the next round of the competition despite starting the day at the bottom of the group.
Given that the match had so much incident, one could call it a crazy game but when Simeone is involved though, it seems to be just another game.
Regardless, the Argentine would have been delighted to see his side progress to the knockout stages, especially after losing star striker Luis Suarez to injury.
The former Liverpool striker was forced off in the 13th minute off the match which then reduced him to tears.
Suarez, though, was smiling at full-time after posting a tweet celebrating his side's win.
In a low-key first half, the game burst into life in the second half when Antoine Griezmann scored from close range after Porto failed to clear a corner.
Then the chaos descended. Atletico winger Yannick Carrasco was dismissed on the 67th minute then Porto left-back Wendell was also issued a red card three minutes later.
Wendell's red card then caused a mass brawl on the bench which also saw Porto's substitute goalkeeper Agustin Marchesin sent off.
Atletico rounded the game off with injury time goals from Angel Correa and Rodrigo de Paul before Sergio Oliveira netted a consolation from the spot to ensure qualification for the last-16.