"It goes to show a week in cricket as we said in Adelaide is a hell of a long time," said Vaughan. "You have to give full credit to the players and the staff for they way we responded the last week.
"Sydney [beating Australia] was a huge day for us and the momentum we took from there straight here was pretty evident. We were patchy at times but that is even more of a positive sign because we have beaten a very good New Zealand team not playing our best cricket.
"There was a real atmosphere around the camp wanting to win this game. We wanted to get to the finals and wanted to play Australia again. It is a great experience for a lot of these lads leading into the World Cup."
Vaughan's calm captaincy in the closing overs was vital to England's success, but there were worrying signs of a limp and more than the occasional feel of his troublesome left leg.
"It was difficult at times but I will be doing work with Dean Conway over the next 48 hours and hopefully playing in the finals," he said. "It is great to be back out there and playing and making a few tricky decisions."
Throughout the series Duncan Fletcher and either Vaughan or Andrew Flintoff have called on the England batsmen to make centuries. Now they have two in the space of two matches after Paul Collingwood ended his post-Adelaide slump with his third ODI ton.
"With the batting, one player has got a hundred and given us the chance to get a good total and in the field we have hunted in packs," said Vaughan. "We have to take all the things from the last two games in to the finals and produce that kind of performance at the MCG, we should put Australia under some pressure."