The Portuguese forward netted a first-half double to put Real Madrid in command at the Bernabeu but his night turned from glory to shame in the 70th minute when he was dismissed for lashing out at Patrick Mtiliga and breaking the Malaga defender's nose.
It was his second dismissal of the season after his sending off against Almeria in December for kicking out at an opponent.
"Cristiano Ronaldo, hero and villain" (El Pais), "Cristiano Ronaldo, again angel and demon" (La Razon) and "Doctor Cristiano and Mister Ronaldo" (Marca), were some of the headlines in Monday's Spanish press.
Marca columnist Roberto Palomar said Ronaldo's behaviour had been his "umpteenth act of idiocy this season" and slammed him for letting the team down with strikers Gonzalo Higuain injured and Ruud van Nistelrooy sold to Hamburg SV at the weekend.
"Anyone who gets sent off against Almeria and Malaga with the match already won is a fool," Palomar wrote.
"Someone needs to sit down with the lad and explain what's what because you can't go through life behaving like that."
Writing in El Mundo, columnist Orfeo Suarez said Ronaldo had to quell his anger for his own benefit and for that of his team mates and the club that paid his massive salary.
"All that is left for him to do now is think about himself, discover how to exorcise his demons so that only the goals remain but without affecting his personality, his hunger," Suarez wrote.
"It's a difficult equation because a good forward without a demon inside does not exist."
Santiago Segurola, another Marca columnist, and Ramon Besa in El Pais both focused on what they said was Ronaldo's obvious desire to eclipse Barcelona forward Lionel Messi, who succeeded him as World Player of the Year in 2009.
"Ronaldo is in as much of a hurry to compete with Messi as Madrid is to catch Barca and take over at the top of the table," Besa wrote.
"That's now two red cards against modest teams, Almeria and Malaga, which is proof of (his) anxiety."
Segurola added: "Ronaldo needs to control his impulses as he'll come up against an infinite number of Mtiligas.
"He's too fast, too strong and too high-scoring. And too nervous. Rivals coaches are taking note. Defenders too."
Ronaldo, who apologised to Mtiliga after the game and said he never intentionally tried to hurt another player, will at the least be suspended for second-placed Real's trip to Deportivo Coruna on Saturday.
"People who understand football know that my intention is always to try and play. The red card is a disgrace I don't understand it," he told reporters.
"I know you saw blood on the TV screens but I was just trying to break free. I never try to hurt anyone."
