Mark Hudson scored the only goal of the game in the forty-first minute, slamming home on the half-volley, while Palace goalkeeper Julian Speroni pulled off a stunning save to deny Stanislav Varga late on.

Keane said: "I don't think we deserved anything. You've got to earn the right to win a game of football and it just passed us by. That makes it all the more frustrating."

He told safc.com: "The game was there for the taking, there's no doubt about that, and we were looking to go on to the next step in terms of getting near the play-offs, but clearly we're not ready for that.

"And, clearly, some of our players aren't ready for the next challenge and that makes it so frustrating."

He added: "You want players who can go and try something and if they are trying to do that they can't be criticised.

"But if they keep going back to the keeper, then they will be criticised - because anyone can do that, and we don't want that at Sunderland."

Palace manager Peter Taylor singled out match-winner Hudson and keeper Speroni for special praise.

Taylor said of the defender: "He's a very good player and he's been doing very well, so we're pleased with him.

"People were maybe a touch negative about him when I first came here, but to me he's a good lad on the training pitch and he's playing very well.

"I thought the one save Julian made from the header was outstanding," he added on the club's website, cpfc.co.uk.

"It was disappointing to give away a free header but Jules has now played two matches and been very good, reading most things well."