Holders Real Zaragoza, league leaders Barcelona, champions Valencia and high-flying Espanyol all fell victim away to lower-ranked opponents in a night of upsets in the King's Cup on Wednesday.
A weakened Barca, missing the influential Ronaldinho and Deco, lost their first domestic game of the season in a shock 1-0 extra-time defeat by third division Gramenet.
The modest Catalan side produced a combative defensive display to keep their illustrious neighbours at bay and force the game into the extra period.
Midfielder Olles became the hero of the night when he made the most of a mometary lapse in the Barca defence to crack home the winner in the 98th minute.
"We took the game very seriously and I cannot fault the attitude of my players," said Barca coach Frank Rijkaard.
"We had a stack of scoring chances but the ball just wouldn't go in the net and I have to congratulate Gramenet for such a good tactical performance."
Nine-man Zaragoza slipped to a 2-1 defeat at Gimnastic, Espanyol lost 5-3 on penalties to Terrassa and Claudio Ranieri's Valencia were dealt their fourth defeat in a row when they also lost to a second division side by going down 1-0 at Lleida.
Atletico Madrid, Real Sociedad and Numancia all had an easier time with comfortable wins over third division opponents.
Real Madrid had already made it safely through to the second round on Tuesday, England striker Michael Owen scoring his third goal in as many games to help his side clinch a 2-1 win over third division neighbours Leganes.
Zaragoza, who claimed a dramatic 3-2 extra-time victory over Real Madrid in last year's final, got off to a dreadful start against Gimnastic when striker Antonio Pinilla scored from a rebound after just two minutes.
SITUATION WORSENED
Pinilla's substitute Fernando made it 2-0 after the break and the situation worsened for Zaragoza when they were reduced to nine men after centre-backs Alvaro and Gabriel Milito were dismissed in quick succession for picking up second bookings.
Midfielder Albert Zapater pulled one back in injury time, but it was scant consolation for the holders who have been eliminated in the first round on five occasions the season after winning the Cup.
Valencia boss Ranieri will find himself under increased pressure after watching a second-string side produce a lame performance against Lleida who were the better team throughout.
Midfielder Albert Crusat scored the winner 16 minutes from time when he outpaced the defence, beat keeper Anders Palop to the ball and looped a deflected shot into the empty net.
Espanyol, fourth in the Primera Liga, were the victims of the first upset when they lost 5-3 on penalties to Terrassa, who held their opponents to a goalless draw despite playing much of the second half and all of extra-time with just 10 men.
