Cristiano Ronaldo has been charged with improper conduct by UEFA after his Champions League crotch-grabbing celebration

Cristiano Ronaldo single-handedly brought Juventus back from the brink of defeat in a stunning Champions League win over Atletico Madrid on Tuesday last week.

The soccer star wrenched the Italian side back from a 2-0 deficit via a masterful hattrick, sending his team into the quarterfinals where they will face Dutch side Ajax.

Naturally, Ronaldo was keen to celebrate his goals - especially after the media scrutiny he faced in the build-up to the game. But the way in which he did so has not sat well with the Champions League organisers, UEFA, who have charged the player with improper conduct.

After scoring, Ronaldo was seen thrusting his hips forward and grabbing his crotch, a gesture that was likely a mocking nod to the Atletico Madrid manager Diego Simeone who celebrated in the same manner after his club's win in the first leg.

Simeone was fined £17,000 ($22,600) for the "obscene" gesture, and later apologized.

Simeone explained to Sky Sports: "It means we have balls, a lot of balls. To start (Diego) Costa and Koke after they hadn't played for a month takes balls.

"I did it as a player at Lazio and Bologna and I did it again to show our fans that we have 'cojones.'

"It wasn't aimed at the other team, I was turning towards our own supporters. It's not a nice gesture, I'll admit, but I felt the need to do it.

"It was such a tough game, we fought so hard and Diego Costa worked really hard when he wasn't 100% fit.

"I had to show what I was feeling. I can only apologise if anyone was offended, but I did it from the heart."

UEFA will rule on Ronaldo's improper conduct case on March 21.