Captain David Beckham said England's two late goals in the 2-0 win over Trinidad & Tobago on Thursday sounded a warning to their World Cup rivals about the strong character of his team.
"We never give up. That is the message we always give out," Beckham told ITV Sport after his side sealed qualification for the second round with a maximum of six points from two games in Group B.
"We knew it wasn't going to be easy today, people expected it to be easy but we knew if we kept at our game plan we would break them down.
"The good thing about the game is that we finished strongly."
England were frustrated by World Cup debutants Trinidad until Peter Crouch and Steven Gerrard scored in the last seven minutes.
Beckham praised coach Sven-Goran Eriksson's decision to bring on fit-again striker Wayne Rooney and wingers Aaron Lennon and Stewart Downing in the second half.
GOOD SUBSTITUTIONS
"The manager made good substitutions," said the Real Madrid midfielder. "It was very positive and we pressed forward from that.
"It would be fair to say you've not seen the best of us yet. We know we can get better and we just have to prove it."
Trinidad coach Leo Beenhakker said he had tried to stifle England's attacking plans.
"We knew we could organise our game to survive for a long period," he said. "We had some small chances, yes, but that is football.
"We can live with it. It [defeat] always hurts.
"England hit long balls at the beginning and we did a very good job defending. But they have fantastic players and I wish them all the best."
Trinidad captain Dwight Yorke was seen chatting and laughing with his former Manchester United team mate Beckham as the two teams waited to go on the field.
Asked what the two players had spoken about, Yorke said: "We have great memories from our three and a half, four years together [at United].
