Australia set-up the last-four showdown after a dogged 11-9 victory over defending champions South Africa - with the Wallabies coming out on top despite having to defend for long periods.
And despite the All Blacks, the tournament favourites, blocking their path to the final, Genia believes Australia can topple their old foes once again.
Australia have won two of their past three meetings, as well as both of their previous World Cup encounters - the 1991 and 2003 semi-finals.
And Genia said: "I'm 100 per cent confident. I don't know if I could be more confident.
"I don't want to sound arrogant, I'm not that sort of bloke. I'm not cocky or arrogant, but I really believe in the guys that we have in this group that we can do it.
"We back each other all the way and we showed on the weekend that we can not only win through skill but also team spirit, wanting to do it for each other. For that fact alone, I have every confidence going into this game."
Meanwhile the 23-year-old Genia insists he was honoured to have played in that gutsy win over South Africa.
"I've never been part of a game like that and won, if you look at the stats alone, you'd think they beat us 50-0," he said.
"It was just won on guts and character and to be honest I'm just so proud to have been part of that performance, to have played that game and won."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
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The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.