Ronaldo also compared the difficulties of goal getting in Serie A to that of the Premier League, which is widely renowned as the most competitive league to play in.
Juventus defender Giorgio Chiellini, making his 500th appearance for the Italian champions, had the ball in the net after four minutes following a goalmouth scramble but it was disallowed for foul by Ronaldo on goalkeeper Jan Oblak.
The excellent Federico Bernardeschi then drove into the penalty area and was brought down by Angel Correa, with Ronaldo stepping up with four minutes to go to convert the spot-kick and down Atletico yet again.
It was Cancelo who supplied the cross on this occasion. Bernardeschi popped up on the left to deliver a wonderful inswinging cross that allowed Ronaldo to overpower Juanfran at the back post and beat Oblak with a downward header. Remember that we had players out, yet this was a great game with what we tried in an incredible atmosphere - the stadium was really our 12th man tonight.
Bayern return to Bundesliga summit with Liverpool looming
Despite some dogged Stuttgart defending, Dortmund took the lead at Signal Iduna Park when Reus netted a penalty on 62 minutes. The strike was Lewandowski's 16th Bundesliga goal of the season, extending his incredible record against Wolfsburg.
It was perhaps a surprise that Diego Simeone's Atletico were overwhelmed so easily.
The first leg result was near ideal, and he'll be telling his team to go on the counter and give him one goal.
The Juve superstar copied Simeone's "balls" celebration in front of the Juve faithful, with the Argentine having celebrated emphatically after his side made it 2-0 in the first leg. He had played with Real Madrid for almost a decade, leading the Spanish powerhouse to four Champions League titles in five seasons, including in the last three.
Atletico failed to have a shot on target in a Champions League game for the first time since December 2008 v Marseille.