(Photo credit: Doha Stadium Plus Qatar)
By the end of the first leg in Turin, the mood around the Juventus camp was one of demoralisation. They had been beaten, heavily, at home, where they have been so dominant for so long in European competition.
The brilliance of Cristiano Ronaldo had left them defeated, 3-0 down at the halfway stage of the tie. "Now it will be impossible," admitted Juventus coach Max Allegri.
It was a frank assessment and one that few will disagree with. Most expect the second leg at the Bernabeu to be little more than a formality.
To progress from this position, Juventus will need, in the words of Allegri, "to produce a top performance". They might be encouraged, though, by Roma's improbable comeback against Barcelona on Tuesday evening.
Here are four things Juventus must do to stand a chance of replicating their fellow Italians and making it, against all odds, through to the semifinals.