Real Madrid star Cristiano Ronaldo spoke of his respect for Sporting CP and said it was why he was unable to celebrate his stunning free-kick.
Ronaldo dragged the LaLiga giants back into the game with his sublime 25-yard effort before Alvaro Morata scored a late winner in the 2-1 victory.
"It was against the team where I learned my trade," Ronaldo said, via the club's website.
"The club has a place in my heart and I have a lot of respect for them.
"That's why I couldn't celebrate it."
But Ronaldo's goal, and substitute Morata's late winner, saw Zinedine Zidane's men come away with victory in their Group F opener.
"We were a bit flat at the start, but such is football and such is Real Madrid and the comebacks are part of this mythical stadium," Ronaldo said.
He added: "This game serves as a warning that we can't be starting games so poorly, because teams will sweep the floor with us and we don't want that.
"We want to finish top of the group and win."
