Wednesday saw Portuguese ace Cristiano Ronaldo walk into his first Champions League game for his new club Juventus. The 33-year-old moved away from Real Madrid in a famous £99 million switch to the Italian side.While Lionel Messi opened his side's Champions League group stages with pomp and a record for the most hat-tricks in the elite competition, his Portuguese counterpart did not have a similar start.Messi went into the game tied with Cristiano Ronaldo in Champions League hat-tricks: each having scored seven. The Argentine is now ahead of the Portuguese in the feat and has now scored 48 hat-tricks in all competitions.The Argentine now has 104 goals to his name in the competition. He has also scored 14 consecutive goals in the Champions League campaign, putting him alongside Real Madrid legend Raul in a joint record.Ronaldo's first Champions League game as a Bianconeri player, on the other hand, made the headlines for all the wrong reasons. During the game against Valencia, which saw the Italian giants win 2-0, the talisman was sent off by the referee only after 29 minutes.The Portuguese appeared to have been involved in a challenge that did not look like much to fans: the 33-year-old appeared to knock Valencia's Jeison Murillo to the ground off the ball, after which the referee, Felix Brych, showed a straight red card.Ronaldo appeared to be in tears after the referee gave him his marching orders.The former Real Madrid man won three Champions League finals in a row with the Spanish side. He also broke individual records during his time at the Bernabeu, becoming the Champions League's all-time top scorer while also being the first man to break 100 goals in the competition.As a result of the red card, Ronaldo could face a three-game suspension, which would see him miss group stage games against former side Manchester United and the BSC Young Boys.Twitter has since exploded with reactions to the decision:This is not worthy of a red card. I’m in shock! @IFTVofficial @ESPNFC @Gelo717 @juventusfc @TheCalcioGuy @Cristiano @ChampionsLeague @Adz77 pic.twitter.com/7TIln6h5r3— Anthony F (@bx_juventino) September 19, 2018UEFA have final say but if they agree with the referee the likelihood is 3 games, like Alli's tackle in the Europa League last season— Tusken (@raider_unknown) September 19, 2018Cristiano Ronaldo got a red card for this... One of the worst decisions in UCL history pic.twitter.com/449Yhp2b8B— 7 (@dr7n_) September 19, 2018I just hope this is appealed and overturned. Goodluck champ— Adeyemi Olumide (@oluprescott11) September 19, 2018Card will not stay. That wasn’t a red card, so im pretty sure they will appeal in uefa!— Zizou (@ZizouHernandez) September 19, 2018Seeing things from this angle changes my mind. It is a red card. Kicks the player, then tries to pull his hair. It’s a red card. Don’t act like a prick @Cristiano. pic.twitter.com/VJ7UfTuLjR— BarcAddicts (@BarcAddicts) September 19, 2018reason of red, off the ball deliberately putting out leg to hurt player and pulling hair afterwards. Definitely not a wrong decision. @ChampionsLeague @UEFAcom @Cristiano #UCL #Ronaldo #Redcard pic.twitter.com/JRm7bNTmQJ— Raniyer Anurag 🇮🇳 (@raniyeranurag) September 19, 2018No. WTF dear referee?And what I love about Ronaldo though: Even he won so many trophies in his career, you still can see how much he lives for football. That passion is just phenomenal.— Datura (@K22258875) September 19, 2018Cristiano Ronaldo's red card is an absolute disgrace. So incredibly harsh. Felix Brych is an absolute clown who decided he wanted to be the center of attention.— EiF (@EiFSoccer) September 19, 2018Hey, @UEFA, great decision to NOT having VAR in the @ChampionsLeague and @EuropaLeague. The red card given to @Cristiano is just another one in the bag of jokes. Oh, and what the actual fuck do goal-line referees do, can you tell?— Mauro Silva (@mGTS85) September 19, 2018Cristiano Ronaldo just got a red card for shouting at a defender for diving. Game’s gone.— Adam Digby (@Adz77) September 19, 2018How is this (inside the penalty box) not a RED CARD?And Cristiano Ronaldo touching someone's hair is a Red Card!Such Shame. He will come back,with more fire.Beware.#UCL #VCFJuve #RMAROM #Juventus #ChampionsLeague #CR7 pic.twitter.com/T4jCLW0Gca— Sunny Sindhu (@sunnysingh695) September 19, 2018