"We've been building our confidence with every game. We didn't have a lot of ball in the Scotland game but we managed to take all our chances.
And even there were times (in that game) where we created chances out of nothing. That was quite a confidence-builder," admitted the Munster man.
"Against Wales we're going to have to own a lot more ball and work harder for tries. We're going to have to up it another gear.
"It's a big game certainly. Two teams with a lot to play for so a big performance is needed (from us) and hopefully it comes.
"Wales are such a challenge. They're coming over full of confidence and playing a lovely brand of rugby. They have everything to play for and it's up to ourselves to beat them."
Wallace, who is edging closer to the 50-cap mark having played in Ireland's last seven games, is relishing the chance to lock horns again with Wales' openside Martyn Williams.
He believes Warren Gatland's success in persuading the Cardiff Blues forward to end his brief international retirement has been key to Wales' revival this year.
Wallace added: "You've guys like Martyn Williams in the Welsh back row, who has been around for a long time. They're very talented guys so we'll have our work cut out for us but hopefully we can match them and better them on the day.
"(Getting Williams back) was a very smart obviously. He's central to everything Wales do and I suppose he's a guy we'll have to watch out for.
"I always like playing against him. You always like playing against the best players."
Ireland have a few world class players of their own, including Paul O'Connell who has recovered fully from a back injury to start Saturday's game.
Delighted his provincial colleague is back fit, Wallace said: "You don't need to say anything about Paul as a player or a leader. He just brings what he brings. It's a great boost for the team to have him back in."