Australia finished second in their pool after they suffered the 15-6 upset against Ireland.
However while Ireland have already returned home following their quarter-final defeat to Wales, Australia are 80 minutes away from another final appearance.
And having restored their reputations with a 11-9 back-to-walls victory over South Africa, Kepu can't wait to take on the All Blacks.
"Ireland was a wake-up call but I think we're progressing since," he said.
"Last week against Springboks, I think we held our weight.
"But we've definitely got to step up this weekend because the All Blacks are definitely the pack to beat."
Australia have won two of their past three encounters with New Zealand - and Kepu believes it is up to the pack to provide the platform for the Wallabies.
"The breakdown is massive, so it will be up to us in the engine room to actually provide the platform and the front-foot ball for our backs," he said.
"For many of the boys this is the biggest game of our careers. It can't get much bigger than this."
Wallabies hooker Stephen Moore shares Kepu's view that Australia must look to dominate up-front, which will include improving a lineout display that proved below average against South Africa.
"The physical battle, the breakdown, those contests are going to be crucial to the outcome of the game," Moore said.
"They are going to come out all guns blazing. and we wouldn't expect anything less.
"We have been working on our lineout this week. We certainly weren't happy with how it functioned against South Africa. They put a lot of pressure on our ball, and we've worked accordingly on that."
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.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.