The fans of the Turin club had yet to see their £99m summer signing produce the sort of displays in Europe that helped Real Madrid to four Champions League titles in five seasons, but that all changed on a thrilling night inside the Juventus Stadium.
Having brought the tie level with two typical headers, Ronaldo capped off another remarkable performance and entered Juventus folklore when he smashed in the tie-winner from the spot four minutes from time, after Federico Bernardeschi had been fouled in the area.
It was his 124th goal in the Champions League and eighth hat-trick in the competition. The home fans erupted on the final whistle and the players rushed to Ronaldo.
“It was meant to be a special night and it was, not just for my goals but for the attitude we showed,” the 34-year-old said.
“That is the sort of mentality you need to win the Champions League.
“This was why Juventus brought me here. To help do things that they have never done before.”
Atletico’s defeat means they miss out on the chance to play the final at their own Wanda Metropolitano stadium on 1 June.
The draw for the last eight will take place on Friday at 11:00 GMT.
Juve coach Massimiliano Allegri set up his team to play a high line and put pressure on their Spanish opponents from the first whistle, with the onus on full-backs Leonardo Spinazzola and Joao Cancelo to advance forward as often as possible.
The home side thought that tactic had paid off early when captain Giorgio Chiellini poked home in the fourth minute. However, following a VAR review it was declared that Ronaldo had fouled Jan Oblak in the build-up.
There was no need to refer to VAR when Juve next had the ball in the net through Ronaldo’s first header past the Slovenian keeper.
It gave the home fans, who were handed 30,000 flags to wave, hope that their side could produce one of the great Champions League fightbacks in recent times.
That became more likely soon after the restart when Ronaldo headed in his second.
