Barcelona defender Gerard Pique rued his side's failure to take a stranglehold on the Liga title race as they lost 2-0 at Real Madrid in Sunday's 'Clasico' after dominating the first half and failing to take their early chances.
Barca went into the game with a two-point lead over Real in La Liga but now find themselves trailing their arch-rivals.
Lionel Messi, Arthur Melo and Antoine Griezmann each missed clear opportunities but Real came out far stronger after the break and second-half goals from Vinicius Jr and Mariano saw them take a one-point lead at the top of the standings.
"We controlled the game in the first half, which was the worst I have seen Madrid play in all the years I have played at the Bernabeu," Pique told reporters.
"We had a chance to make a real statement and if we had taken our chances they would have had a mountain to climb.
"They come out of this game feeling very strong while we feel down but we are not out. I think there is still time for us to win the league."
Real captain Sergio Ramos underlined the importance of the victory for his side after a week in which they were reeling from a Champions League last 16, first-leg defeat at home to Manchester City and a shock 1-0 Liga loss away to Levante.
"This was a unique opportunity to put our own fate in our own hands for the rest of the season, against a brilliant side but with our fans on our side," he said.
"We were relentless in the second half and once we got the goal we made sure we didn't sit back and instead we set out to kill the game off and that's what we did.
"When results don't go your way you feel in debt to the fans and we needed a day like this. We wanted to win and now we want to make it count by winning the title."