John O'Shea has backed Republic of Ireland to shine against champions Spain on Thursday.
Giovanni Trapattoni's men face an uphill challenge to progress from Group C after Sunday night's 3-1 defeat by Croatia.
Next up is the daunting task of taking on the world and European champions but O'Shea believes they can emerge from the game with some tangible reward.
The defender said: "Yes, without a doubt. We have done it in the past against the top teams and were good enough to get results and we will have to do that again.
"Our backs will be against the wall for probably the majority of the game, but that's normally when we come out and shine.
"We are going to have to keep our shape - the team shape is going to be so important against Spain because they can cut you open - and staying with the runners, not following the ball with the one-twos, is a massive thing.
"Obviously, the Barcelona trait is very evident through their team, but they have got some great attacking players.
"We will have to be on our game, but I am confident we can cause them some problems too."
The 31-year-old has waited a long time to go to the finals of a major tournament and admits he will only start enjoying it if they get results.
He added: "You can't enjoy it when you are not winning football matches, unfortunately.
"If we get a positive result against Spain, that will put a different complexion on it.
"We can't lose the game, we know that, depending on the other results.
"We can beat Spain, but we are going to need a lot of luck along the way and we are going to have to play better too."
Despite the daunting task, O'Shea is relishing taking on some of the best players in the world.
"That's the reason you play football and why you look forward to going to training every day," he said.
"If you can't test yourself against the best... We will certainly be doing that against Spain.
"Look, you are coming to an elite competition, the cream of Europe, and you have a chance to play against some of the best players in the world.
"Spain have proved it - they have won the European Championships, they have won the World Cup, so they have proven how good they are, and we have got the chance to show our stuff against them.
"What more is there to look forward to than a game like that?"