David Campese admitted England deserved their victory over Australia in Melbourne on Saturday and said their performance was good for the game.
The England team had been attacked for their displays Down Under, and former Wallabies wing Campese was among their most vociferous critics.
After Jonny Wilkinson kicked them to victory over the All Blacks in the rain of Wellington, Campese told this website England played boring rugby and were bad for the game.
But he admitted he had been proved wrong after their stunning 25-14 triumph in Melbourne.
"I've been giving the English a hard time but they came out three tries to one and dominated the game," he told BBC Radio Five Live.
"The Wallabies have got a lot to think about before the World Cup but tonight it was England's night.
"It was a step up (in class). They proved me wrong which is fantastic and the good thing is they had a go.
"The Wallabies probably thought they had England's measure but they kept on going, they found the gaps."
Campese did have a word of warning, however, for the visitors, saying the southern hemisphere teams would improve significantly by the time of this year's World Cup.
"The thing I'm worried about is, England go home and they have a rest in the summer," he said.
"We're going to start the Tri-Nations - Australia, New Zealand and South Africa will improve a lot.
"We wait to see how England fare after their break."
But he said England's win was good for the game.
"I think for world rugby it's great. We've now got contenders for the World Cup from the northern hemisphere," he said.
"We have northern hemisphere teams that can give it to us on our home soil."