MADRID, Spain - Eneko Romo's last-minute goal propelled third-division Real Union past a stunned Real Madrid in one of the greatest upsets in Copa del Rey history on Tuesday.
Raul Gonzalez's hat trick led Madrid to a 4-3 victory, but Romo's 90th-minute header put the Basque club into the last 16 on away goals with the aggregate even at 6-6.
Raul looked to have put Madrid through in the 86th when Union goalkeeper Edouard misplayed the Madrid striker's long pass into the area for the ball to bounce under him.
Madrid, which hasn't won the Spanish knockout competition since 1993, twice rallied from deficits at Santiago Bernabeu Stadium.
Real Union, a three-time champion but not since 1927, earned the initiative 14 minutes in when Paul Abasolo controlled Pablo Garcia's high cross to half-volley under Madrid goalkeeper Jerzy Dudek.
Raul drew Madrid even in the 36th after catching out Edouard with a header, but Union went ahead again in the 49th when Asier Salcedo slipped his marker to go clear through and score from Manu Garcia's long ball.
Raul rallied Madrid again two minutes later after getting a toe out to score from Javier Saviola's centring pass.
Alberto Bueno, who plays for Madrid's youth team, fired a powerful shot over Edouard into the far corner of goal to put Madrid ahead for good in the 68th with his first senior score.
Madrid's leaky defence has allowed six goals in its past two games.
Villarreal, Sevilla and Racing Santander must score home victories this week to avoid exiting alongside Madrid.
Villarreal has the toughest task with a 5-0 deficit to overcome against third-division Polideportivo Ejido on Wednesday, while Santander is 2-1 down to second-division Murcia.
Sevilla must reverse a 1-0 deficit to Ponferradina on Thursday, when Osasuna and Getafe also meet after a 0-0 first-leg draw.
League leader Barcelona holds a 1-0 lead over third-division Benidorm, while defending champion Valencia beat Portugalete 4-1. Both play on Wednesday as well as Atletico Madrid, which has a 1-0 lead over Orihuela.
Real Union pressured early with Dudek stretching to tip Sainz's dipping drive wide in the fourth.
The Irun-based club continued to press after taking the lead, with Manu Garcia clear through from Manu Sainz's defence-splitting pass in the 19th, but a poor first touch allowed Dudek to cover.
The Basque minnows slowed the tempo and Madrid finally exploited after Marcelo picked out Raul for his first goal.
Manu Garcia chested to the goal-line in the 42nd to nearly score from the tight angle. Two minutes later, Javier Saviola was wrongly ruled offside after heading home the rebound from Raul's initial shot.
Moments after substituting Fabio Cannavaro, Javi Garcia headed wide from close before allowing Salcedo to slip away and go clear in on Dudek for Union's second.
Gonzalo Higuain, who scored four goals in Madrid's 4-3 league win over Malaga last Saturday, entered for Saviola with eight minutes to play and nearly rolled the goal the host needed in injury time.
In Wednesday's other fourth-round games, it's: Valladolid versus Hercules; Almeria versus Rayo Vallecano; Espanyol versus Celta Vigo; Real Betis versus Castellon; Deportivo La Coruna versus Elche; Sporting Gijon versus Numancia; Mallorca versus Malaga; and Athletic Bilbao versus Recreativo Huelva.