Juventus fans went through a rollercoaster of emotions on Saturday, as the Bianconeri slipped to a 2-1 defeat against Napoli to continue their faltering start to the 2021-22 Serie A campaign.On the other hand, Cristiano Ronaldo, who left the Allianz Stadium to return to Manchester United this summer, enjoyed a dream second debut at Old Trafford. The 36-year-old scored what turned out to be a crucial brace for Manchester United in a 4-1 victory against Newcastle United.Ronaldo received rave reviews for his performance as Manchester United fans took to social media to lavish praise on one of the greats of the game.Ronaldo scored more goals in one game for Manchester United (2) than Juventus has points this season (1). I can’t believe people told me HE was the problem of Juventus.— JClub 🇮🇹 (@blvckgianni) September 11, 2021"Was there a day more utopian, more utterly ideal in the recent life of Manchester United......Ronaldo rose to it, Fernandez decorated it, and Lingard finished it in style." Peter Drury 🔥🔥— KIPCHUMBA MURKOMEN, E.G.H (@kipmurkomen) September 11, 2021Today Cristiano Ronaldo became the first player to score 2+ goals in a Premier League game at Old Trafford in Manchester United's No. 7 shirt since Cristiano Ronaldo against Tottenham in April 2009.— Richard Jolly (@RichJolly) September 11, 2021The Juventus fans, meanwhile, expressed their displeasure and indicated that they missed the Portuguese star, who scored goals consistently for the club during his three-year stint in Turin.Juventus have 1 point from 3 games and have lost both their games since Ronaldo left but some of their fans were celebrating him leaving 🤣— 🌊™️ (@RealistGlizzy) September 11, 2021🚨⚽️ | Minutes needed for Ronaldo to score his first goal for a club:Sporting – 206’Manchester United – 566’Real Madrid – 35’Juventus – 320’Manchester United (2nd debut) – 47’— Football For All (@FootballlForAll) September 11, 2021Cristiano Ronaldo since leaving Juventus: 2 Games4 GoalsJuventus was holding him back. pic.twitter.com/QjSTIZ6ymC— CR7 Rap Rhymes (@cr7raprhymes) September 11, 2021I hope all the Juventus fans realize the problem is within their team and Ronaldo was literally bailing them out all this time.Ronaldo didn't hold Juventus back but Juventus definitely held Ronaldo back.— CR7 Rap Rhymes (@cr7raprhymes) September 11, 2021Ronaldo's much-awaited Manchester United return was the major talking point ahead of the Premier League weekend. The Portuguese star rose to the occasion with two goals either side of half-time and revealed after the game that he did not expect to get himself on the scoresheet twice."I didn't expect to score two goals, I only expected one. It was an unbelievable welcome that this crowd gave me. The supporters sang my name all game so I was very nervous but I belong to this club so I want to help the team."Cristiano Ronaldo silences Juventus doubters on Manchester United returnUdinese Calcio v Juventus - Serie AEarlier this month, Juventus legends like Alessandro Del Piero and Fabio Capello turned on Ronaldo for his decision to leave the Allianz Stadium for Manchester United. At the time, a handful of fans even took to social media to say that Ronaldo was holding Juventus back.However, his doubters have gone quiet in the past 12 hours or so as he re-announced himself to the Premier League in incredible style. Ronaldo is one of the greatest players of all time and scored goals regularly despite his failure to spearhead Juventus to UEFA Champions League glory.His Manchester United move was rather unexpected, but Juventus fans who referred to him as the problem have been quickly silenced.