By Simon Evans

IRENE, South Africa (Reuters) - After a season of giant-killing with English club Fulham, United States midfielder Clint Dempsey believes he can help upset the form book again in Saturday's World Cup Group C opener against England.

Dempsey, who helped unfancied Fulham to the Europa Cup final with a memorable win over Juventus in the last four, told reporters that he sees a number of similarities between the attitude and tactics used by his club and country.

"We stick to what we are good at...we have been the underdogs with both Fulham and the U.S. and the most important thing is to have the kind of players who believe they can win no matter who they are playing against," he said on Tuesday.

"That is the kind of team I want to play in - with that kind of attitude you always have a chance against whoever you play.

"At Fulham we stay compact defensively and we have two solid banks of four and choose our moments when we go forward, the U.S. team plays similarly to how we do at Fulham," he said.

Dempsey senses a greater sense of self-belief in the U.S. squad, particularly since last year's run to the final of the Confederations Cup final in South Africa.

"We have players who have played in big games, played in big leagues and have had success - you take that confidence with you and it helps you to keep moving forward.

"No-one thought we were going to get to the final of the Confederations Cup but we did that - no-one thought that Fulham were going to get to the final of the Europa League and we did.

"It doesn't matter what anyone thinks of us, it matters what everyone within the group thinks of themselves. If you have belief that is contagious and people think 'why not'?

"You can't live life in fear, you have to go out and take advantage of your opportunities and do something special, I think the guys here have that mentality," he added.

Dempsey is likely to line-up against England's attack-minded right-back Glen Johnson and he thinks the defender's positive approach could hand the Americans a chance on the break.

"He is definitely effective going forward but when he goes forward you get the chance to get them on the counter.

"Any good team has to worry about when their full backs go forward because there are going to be holes in that pocket that he left open.

"We have to make sure that we have players who are aware of that and can move the ball in that direction because there will be a hole," he said.

(Editing by Justin Palmer)