Real Madrid who has won the tournament for two years in a row, became the first team ever in the history of the competition to defend their title when they did in 2017.
Navas had to get down low to keep out a Muller header as Madrid's nerves were further jangled, but a defence that never looked secure withstood the pressure to put Los Blancos within 90 minutes of a fourth European crown in five seasons.
"I think they were floundering for every cross and for every long ball, so we know what we have to do", Bayern striker Sandro Wagner said.
Marcelo and Toni Kroos both weaved their way into Bayern's six-yard box, but failed to pick a final pass, while at the other end, Vazquez was enduring a torrid time at right back.
Sloppy defense was key for Real's home struggles both against Juve and against Bayern a year ago.
Bayern players then seemed to take their scoring boots off, because they were terrible for much of the next hour.
Burnley near Europa League spot despite Brighton draw
It takes organisation, delivery of performance, the mentality to take on each game, and we've had that in abundance". Brighton were able to steal a point from Tottenham last weekend but have struggled over their last five games.
Bayern paid attention to Madrid's recent struggles.
There had been plenty throughout the first-half to give Bayern hope but, after spending most of the tie being let down by poor finishing, they then self-destructed quite spectacularly defensively.
With regular right back Dani Carvajal missing with a hamstring problem, Zidane faces a selection headache given replacement Nacho has sat out the past month with a thigh injury.
"This is a semi-final", Zidane added.
"It could be an option", Ramos said. It will not represent a successful season if they fail to win a trophy.
According to the Mail Bale is falling short of a place in the starting 11 because of players like Isco, Marco Asensio and Karim Benzema, who have been used much more frequently by Zidane this season. Bayern, five-time European champions, are looking to return to the final after four seasons.
"We need to minimise our mistakes and we want to change a few things from the first leg".
Here we look at some of the issues ahead of the game.