Mourinho, 63, who managed Porto from January 2002 to June 2004, famously winning the Champions League, took over at Benfica earlier in the season.
Leandro Barreiro scored in the 88th minute to ensure Benfica’s unbeaten season remained intact, but that wasn’t the most dramatic moment of the night.
Just a few moments later, after a heated argument with those in the opposite dugout, Mourinho picked up his second red card since joining.
Speaking to reporters after the game, Mourinho clarified the situation, saying: "The referee said he sent me off because I kicked a ball towards the FC Porto substitutes' bench.
“That's completely false. Many times, in our goals, I kick the ball towards the stands to give a lucky fan a chance. I know I'm not very good technically, but it was meant for the stands.
“I was wrongly sent off. The fourth official did a terrible job throughout the game and continues to do so when I told the referee that.”
He then confirmed that his ire was aimed at Lucho Gonzalez, former Porto midfielder and now coach.
"He called me a traitor 50 times. I'd like him to explain to me, a traitor to what? I went to FC Porto, I gave my soul to FC Porto, I went to Chelsea, I went to Inter, to Real Madrid, I went around the world and gave 24 hours of my life every day. That's called professionalism.,” he said.
”When he went to Marseille, was he a traitor? A traitor to what? He could have insulted me in a way that I would have accepted better, but I think it was an attack on my professionalism, which is something I value so much."