However, Brazilian winger David Neres conjured a stunning equaliser nearly immediately after half-time to give Ajax a draw that was the very least they deserved. "The draw is a result, which allows us to have a better position for the away game".
But perhaps even more impressively, it drew him level with Zlatan Ibrahimovic with the most Champions League goals at Ajax's home ground on six.
"If we play the way we did in Madrid, with a lot of courage, then we have a big chance of winning".More news: NYC's New Policy on Measles Vaccine Prompts Renewed Focus in NJ
Forwards Paulo Dybala and Douglas Costa came off the bench at Ajax ahead of highly-rated teenager Moise Kean, who had scored five goals in as many games for Juventus.
Ronaldo hadn't played since injuring his right thigh while on worldwide duty with Portugal last month but he showed no signs of a problem.
Juventus coach Massimiliano Allegri says: "Ronaldo has trained well and is available".
Hakim Ziyech was a thorn in Juventus' side and he produced two good shots from range before forcing Wojciech Szczesny into a fine save when he finished off a spell of pressure by curling a 20-yard effort towards the top corner.More news: Crude Oil Bulls Seeing Few Clouds on the Horizon
One player praised by the Juve manager after the game was Ajax midfielder and Barcelona-bound Frenkie de Jong, with the Italian describing the 21-year-old as the "source of their game".
To add, PSG and Tottenham, who only really started playing regular Champions League football around a decade ago, have both failed to match Ronaldo's goals haul.
The 34-year-old forward scored his side's only goal in the 45th minute of the meeting, but David Neres 46th minute equaliser cancelled out the Portuguese's first half goal. But his heavy touch allowed Neres to rob him and he outpaced the defender, before turning inside and firing powerfully into the far corner.
Szczesny swatted away a blast from Jurgen Ekkelenkamp before Costa hit the woodwork at the other end with a long, angled shot and Onana palmed away another risky effort from Cancelo. Ajax are still very much in the tie, although left-back Nicolas Tagliafico will be suspended for the return after being booked here.More news: Attorney General Barr tells Congress that 'spying' on Trump campaign 'did occur'