Zinedine Zidane lamented Real Madrid's loss of concentration against Manchester City but insisted the Champions League last-16 tie is far from over following a 2-1 defeat.
Madrid collapsed at home to Pep Guardiola's City, who scored twice in five minutes late in the second half to snatch the momentum after the opening leg on Wednesday.
Winners of four of the past six Champions League titles, LaLiga giants Madrid earned a 1-0 lead courtesy of Isco on the hour-mark at the Santiago Bernabeu.
But Madrid saw their advantage crumble away as Gabriel Jesus headed in a 78th-minute equaliser before Kevin De Bruyne completed the comeback via the penalty spot five minutes later, with Sergio Ramos' late red card compounding Zidane's woes.
"We're gutted to have lost, but we know the tie is over 180 minute and no matter what happens that's the way it is," head coach Zidane told reporters. "Even if we'd won. We did the hard work scoring, and then in 10 minutes they scored two."
Madrid captain Ramos will miss the return leg in Manchester after bringing down Jesus with four minutes remaining and Zidane said: "That's football. We can't change it. We need to focus on the positives.
"In a result like that there aren't many positive things, we played well but for the last 10 or 15 minutes. Now we need to go there and win if we want to go through."
"They are mistakes and you pay when you make mistakes," Zidane continued. "That's it. But mistakes are a part of football and that's the way it is.
"We gave everything on the pitch, we lacked 10 minutes of concentration more. It was a very physical, even game and at the end we paid for it."
Madrid, who have only won one of their past five fixtures across all competitions, will travel to the Etihad Stadium to face City on March 17.