Carlo Ancelotti said he still believes Real Madrid can retain their title despite falling nine points behind La Liga leaders Barcelona following a damaging 0-0 draw away to Real Betis.
After the Catalans beat Valencia 1-0 earlier to extend their lead, Madrid needed to win at the Benito Villamarin to maintain the seven-point deficit they started the weekend with.
Reigning Spanish champions Madrid forged the better openings and turned the screw in the final stages, but could not find the goal they needed to stay as close as possible on Barcelona's tail.
Karim Benzema had a free-kick strike disallowed for a handball by teammate Antonio Rudiger, while Betis goalkeeper Claudio Bravo made fine saves to deny the French forward and Vinicius Junior.
"It's quite evident what we're lacking, we have to be more efficient," Madrid coach Carlo Ancelotti told Movistar.
"Sometimes opponents close up at the back, but we have the quality and we have to do it better."
The coach did not think his team's title defence was over, despite the setback.
"It's not impossible. It's very difficult, but we have no doubt we will try until the end," added Ancelotti.
Thibaut Courtois was also forced into two superb stops by Betis who showed why they are in contention for a Champions League place next season with a hearty performance.
"We lacked a bit of accuracy in the final third, the last pass to create clearer chances and we don't leave here happy, at all," Madrid defender Lucas Vazquez told Movistar.
"No [the league is not lost], we're in March, we know it is complicated and we will fight until the end because we truly believe that we can turn it around."
Madrid winger Vinicius Junior, as has become customary in La Liga, was engaged in a running battle with the Betis defence.
The Brazilian has not scored away from home in the top flight since August, but brilliantly set up Benzema at the start of the second half with former Barcelona stopper Bravo parrying the effort.
It was Madrid's first shot on target since last weekend's 1-1 draw against Atletico Madrid.
Los Blancos have scored just once in their last three games – from a corner.
"I'm more upset than angry," said Ancelotti. "I'm upset that this team, with this quality, can't score a goal in three games [from open play]."
Courtois made a stunning save to thwart Borja Iglesias at the other end, when the striker seemed poised to score.
"We had moments in which we had clear openings, my chance with Thibaut," Iglesias told Movistar.
"That's why this guy wins what he wins – he saves a lot."
