Alvaro Arbeloa said Cristiano Ronaldo's late consolation goal in Real Madrid's 2-1 Copa del Rey loss to Celta de Vigo was vital.
The Portugal international netted after 87 minutes of play to help Los Blancos back in the two-leg tie, and Arbeloa is confident that Madrid will eventually progress to the next round following Ronaldo's late strike.
"The goal from Cristiano Ronaldo keeps us in the running to qualify, although it was a shame that we did not score another," Arbeloa told the Real Madrid website.
"Celta were very effective. They play some fine football and it was a complicated match. Our opponents are really putting the pressure on us in our away matches this term.
"However, we're confident we'll fight our way back at the Santiago Bernabeu with the support of the fans."