Real Madrid suffered one of the most disastrous nights in their long history as they were knocked out of the Spanish Copa de Rey by Real Union on Tuesday night.

Real Madrid's Alberto Bueno (2nd L) celebrates a goal with team mates during their Spanish King's Cup soccer match against Real Union Club at the Santiago Bernabeu stadium in Madrid Nov. 11, 2008. [Xinhua/Reuters]

Although Real Madrid won the return leg of their cup tie by 4-3 in the Santiago Bernabeu stadium, the fact they lost the first match 3-2 away to the Basques two weeks ago means they go out of the competition on away goals conceded.

Real Union plays in group one of Spain's Segunda B, effectively the third category of Spanish football, and the defeat is a huge blow to a Real Madrid team that has not won Spanish football's knockout competition since 1993.

A last minute goal from Real Union's Eneko Romo sealed Madrid’s fate and gave the visitors a historic result in the Bernabeu.

Real Madrid's Raul (R) reacts during their Spanish King's Cup soccer match against Real Union Club at the Santiago Bernabeu stadium in Madrid Nov. 11, 2008. [Xinhua/Reuters]

Real Madrid had been moments away from qualifying after Raul Gonzalez had put them 4-2 ahead after 86 minutes with a left foot shot from outside of the area.

That goal was the Real Madrid captain's third of the night, but in the end his hat-trick was to count for nothing.

The game had got off to a dreadful start for Real Madrid after their visitors opened the scoring after just 13 minutes thanks to a goal from Paul Abasolo.

Raul levelled matters with his first of the night 10 minutes before half time, but Asier Salcedo restored Real Union's lead five minutes after the break.

Once again the Madrid captain brought his side level after 51 minutes and when Alberto Bueno made it 3-2 after 68 minutes, Real Madrid looked to be on their way to the next round.

Raul's hat-trick appeared to have sealed matters, but there was still time for Romo to score the last goal of the night and condemn Real Madrid to a humiliating cup exit.