However harsh the decision might have been, the Real Madrid star made things worse by pushing the referee and must sit out five games.
Pending an appeal, Ronaldo will miss Wednesday's second leg of the Supercopa against Barcelona and La Liga games against Deportivo Coruna, Valencia, Levante and Real Sociedad.
The four La Liga games were tacked on to the one-game suspension for Ronaldo's 10th red card of his career.
The Portuguese star will be eligible to play in the UEFA Champions League but won't be back in action for Real Madrid in domestic play until Sept. 20.
The red card and suspension overshadowed what was another big win for Real Madrid after it struggled on its U.S. tour, going winless after 90 minutes in four games.
Real Madrid beat Manchester United, 2-1, to win the UEFA Super Cup and defeated Barca, 3-1, on Sunday.
Ronaldo's first yellow was for taking off his shirt to celebrate his goal to make it 2-1. Another sub, 21-year-old Marco Asensio, capped a big second half for Madrid with a thunderbolt from outside the area in the 90th minute.
"Asensio doesn't surprise me," said Real Madrid coach Zinedine Zidane. "What he does is phenomenal. He's fast and strikes the ball very well."
Asensio was just one of several players Zidane singled out.
"We're happy with him and with everyone," said Zidane, who had his contract extended after Real Madrid returned home from its tour. "It's not easy to come on like that for 15 minutes. He came on and was quickly in to the match and made the difference. Isco, [Mateo] Kovacic and everyone else had a great game."