Arsenal skipper Kolo Toure was critical of referee Eric Braamhaar as The Gunners lost their 28-match unbeaten run in Seville.
Braamhaar awarded the Spaniards a second-half penalty converted by former Spurs striker Fredi Kanoute as Arsene Wenger's men went down 3-1 in Andalucia.
He also sent Wenger to the stands as the Gunners boss became increasingly frustrated with the theatrical antics of the home side.
Toure, who manfully marshalled a weakened Arsenal defence, said: "We gave everything. I don't like to talk about the referee but tonight he was a little bit difficult for us.
"The ref sometimes helped them but when you go away it is always like that but they deserved their win. We gave everything but that's the way football goes.
In spite of surrendering their unbeaten record which stretched back to 7th April, Toure feels the Gunners will bounce back quickly.
"We knew that defeat would come but we need to start again and show character. To be a winner you need to come back from these hard things."
The visitors were leading in Seville thanks to Eduardo da Silva's 11th minute goal but once the hosts got back into the game thanks to Seydou Keita's fine strike it was always an uphill struggle for the inexperienced visitors who fielded a much-changed line-up.
"We played against a really good side," said Toure. "We were leading and then we conceded and from there the game started going badly for us. We'll now move onto the next game."