A two-goal fight back kept alive Middlesbrough's dream of repeating their Carling Cup final triumph of two seasons ago.
Boro deserved their win over Palace but they had a first-half scare when Franck Queudrue put through his own net to hand the away side the initiative.
There was no sign of danger when the defender met a left-wing cross from Jobi McAnuff but inexplicably he put it into his own net from six yards.
Middlesbrough enjoyed the balance of attacking play in the first half but the Palace defenders covered well and Julian Speroni was not severely tested in goal.
There was a lack of atmosphere in the ground with a below average crowd under 11,000, despite reduced admission prices.
Palace went ahead through Queudrue's own goal after 31 minutes.
Middlesbrough sought an immediate response and Speroni parried a Fabio Rochemback effort.
Andy Johnson was lively in the Palace side and was often prepared to dash back to help his defence.
Middlesbrough concentrated on right-wing attacks but only pestered Speroni once in the opening half with the goalkeeper making a brilliant save from a powerful Mark Viduka shot.
There was some booing from a section of Middlesbrough fans as the teams walked off at the interval.
Palace brought on substitute Clinton Morrison for Johnson immediately after the break. Possibly Johnson was feeling the effects of a knee injury after a long period out of the game.
Middlesbrough finally achieved the breakthrough with a cracking goal by Viduka.
The Australian skipper left Speroni helpless with a brilliant shot from 25 yards.
Three minutes later Boro were in front. Viduka supplied the pass and Szilard Nemeth the finish.
Jimmy Floyd Hasselbaink rattled the post with a fierce shot immediately after.
Nemeth was injured three minutes after his match winning goal and was replaced by Emanuel Pogatetz.
Viduka made a hash of his shot and then acknowledged his wasted effort.
Palace made changes in a bid to turn the game around but they lacked menace in attack.
Credit to the Palace for their defensive work, but manager Iain Dowie must have been disappointed with the limited attacking threat.