Coach Carlo Ancelotti said Real Madrid will need "patience" and the full support of the Santiago Bernabeu Stadium when they host Juventus next week, looking to secure a second successive Champions League final.
Real were crowned European champions for a record 10th time last year with a 4-1 drubbing of city rivals Atletico in Lisbon.
But a 2-1 defeat by Juventus in Turin on Tuesday - complete with an opening goal from former Real Madrid striker Alvaro Morata - has given the Spanish giants food for thought ahead of next week's decisive return leg.
Morata, who moved to Juventus in the summer, refused to celebrate when he opened the scoring with a tap-in after goalkeeper Iker Casillas had pushed Carlos Tevez's angled strike into his path.
Cristiano Ronaldo, with his 76th goal in the competition, levelled on 27 minutes with a simple header as Juve's defence went missing, only for Tevez to seal the win from the penalty spot just before the hour, after being felled in the area.
Real have the benefit of a precious away goal, but after seeing his side struggle to find their feet before finally taking command when it was already too late, Ancelotti said he expects a different Real side on Wednesday.
"We made more mistakes than normal, that was because of Juve's pressing. Their line was higher in the second half," said Ancelotti.
"But we'll be confident because we are playing at home and the fans there will help us. We have to be patient. The result is a negative one but not such a bad one."
Juve coach Massimiliano Allegri could have influential French midfielder Paul Pogba - a target for Real and several other major European sides - back in time for the return leg.
But the Italian insisted that, without a goal, Juve's chances of reaching the final in Berlin look slim.
"Next Wednesday, we'll be up against an extra motivated Real side. I want to repeat, we have to play better than we did tonight. We have to score against them, otherwise reaching the final will be difficult."