Celta Vigo stunned Atletico Madrid with a goal after three minutes and went on to claim a creditable 1-1 draw in their Copa del Rey quarter-final first leg at the Vicente Calderon.
Roberto Trashorras struck early on to give the struggling Segunda Division side a shock lead. Tiago levelled for the hosts eight minutes later, but the Primera Division side could not find a winner.
Walter Pandiani's late strike gave Osasuna a valuable away goal as they lost 2-1 at Racing Santander in their quarter-final first leg.
The Uruguayan forward finished off a counter-attack in the 89th minute after his goalkeeper Roberto had been left rooted to the spot by two stunning strikes from Racing.
Gonzalo Colsa scored with a powerful shot from outside the area in the 63rd and Senegalese midfielder Papakouli Diop caught Roberto off his line with a curler from distance in the 84th.
In the other two ties, Sevilla took a giant step towards the semi-finals by winning 3-0 at Deportivo Coruna on Wednesday while Getafe won 2-1 at Real Mallorca.