Espanyol maintained their 100 percent record in Group F with a 2-0 win at The Amsterdam ArenA over Ajax.
The Dutch giants could themselves have moved top with victory, but they were humbled by the Barcelona outfit.
Goals in either half from Walter Pandiani (36) and Ferran Coro (78) were enough for Ernesto Valverde's men to claim victory.
Austria Vienna have bowed out of the competition after lost 1-0 at home to Sparta Prague.
The only goal of the game came after 11 minutes when former West Ham star Tomas Repka pounced.
The win does little for Sparta - who need Ajax to lose heavily in their final game if they want to progress.