"We understand we can't play the same way we did last week - we've got to be better if we want to win," Genia said.
"They're going to be better. We've made a huge point of that and we really emphasised that at training."
While Wales have made four changes in their bid to level the series, Australia will field an unchanged line-up in Melbourne.
"The consistency and cohesion within the structure of our attack worked really well," Genia added. "You have the same players inside and outside of you and knowing that it worked last week, you have confidence in the group and what we've done."
Wales assistant head coach Rob Howley has already proclaimed his side will have to quell the threat the diminutive halfback poses, but Genia is unfazed by the prospect of having a target on his back.
"I'll just go out there and do my job as best I can. If there is extra attention you've just got to deal with it," he said.
"I think an area where they will target us is probably our breakdown. They'll look to slow the ball down a little bit so that we don't get the momentum we had last week.
"We've had a big emphasis on that at training this week."
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