England were downed in convincing fashion by their fiercest rivals at Lord's last month and looked in serious danger of missing out on the semi-finals at their home tournament.
However, back-to-back wins over India and New Zealand turned the tables and have put England in world on a collision course with Australia at Edgbaston in the second semi-final on Thursday.
England have lost their last two clashes with Australia including a warm-up game before the World Cup began, but before that Root and co had the edge with a series win Down Under and a 5-0 whitewash on home soil.
"If you look at the past 11 games against them we have won nine," Root was quoted as saying by the ICC.
"These guys and this group over the last four years, their experience against Australia have been very positive and they have got a lot of success in the bank.
"I don't see that as a big worry for this group, we will be drawing on that confidence that over a long period of time now we have been successful against Australia and we should take that into Thursday."
Add to that the fact that England have found their best form - with Jason Roy back firing fit at the top of the order - and the mood is clearly buoyant.
"I feel we are in a good place coming into it, I feel like the last two days have almost been like knockout cricket for us.
"We have been playing in a high-pressure environment for a while now and hopefully that will hold us in good stead going into this game.
"It doesn't matter (who are the favourites). It comes down to who plays their best cricket on the day. If we play in the manner we have the last two games, we will be a very difficult side to play against.
"You can look at form, statistically who is stronger, but it all comes down to who handles the day better, who plays the stronger cricket for the longest period and who will stand up and be victorious at the end of it," Root added.