Italy striker Mario Balotelli said Cesare Prandelli's men are a force to be reckoned with after a first-up FIFA World Cup win.
The 2006 champions edged England 2-1 in Manaus to kick off their campaign in fine style, with Claudio Marchisio and Balotelli goals helping Italy to a crucial three points.
Balotelli said the performance should put some of the heavyweights in Brazil on notice.
"It's a unique experience, I've never played a World Cup, now it's fantastic," the Milan man said.
"My goal is dedicated to my future wife and my friends who are at home.
"This game was very difficult for the climate and because England is strong: Italy suffers more, this is typical of our national team, but the important thing is to win and we did.
"We do not fear anyone. The others who must fear even Italy.
"But we must only think about Costa Rica, but we have to be quiet because otherwise we're not going anywhere."
Roma stalwart Daniele De Rossi said he was thrilled to go up against England mainstay Steven Gerrard, and he also hailed Balotelli's quality after the 23-year-old scored the winner at the Arena da Amazonia.
"For me is always fantastic to play against Gerrard. He is a world class champion. We are very happy for the win," De Rossi said.
"Mario? He has the numbers of a world class player.