Manager Ole Gunnar Solskjaer says Cardiff need a "miracle" to avoid relegation from the Premier League after they lost 3-0 at home to Crystal Palace.
Promoted from the Championship last season, Cardiff are six points adrift of safety with five games remaining.
"We need to produce a miracle to stay up now," said Solskjaer.
"There was a lack of belief a little bit towards the end. We ran out of ideas."
Jason Puncheon scored either side of a goal from Joe Ledley, playing against his former club for the first time since he left for Celtic in 2010.
"It was a big game for us and I am very disappointed for the fans and players that we ended up with a performance like this," said Solskjaer.
"I am full of fight. If you produce a miracle - that sometimes happens in football - you are still capable of getting out of this and staying in the Barclays Premier League.
"It has been a tough season for everyone involved with the club. In the second half it showed a little bit that it has taken its toll."
Palace's victory - their second in succession following their shock 1-0 win over Chelsea last week - lifted them into 14th place in the table, seven points clear of the relegation zone.
"It was a good performance," said boss Tony Pulis.
"We knew Cardiff would be strong and get lots of balls in their air, but our two centre-halves and two central midfielders were outstanding.
"We played really well against Chelsea last Saturday and we didn't want this to be after the Lord Mayor's Show.
"It is very rewarding for everyone. That said, we still have six games to go and we are not safe. The game against Aston Villa on Saturday is massive."