It was a brave effort from the world's 17th-ranked team and Wallace readily admits that he was impressed by not only Georgia's physical qualities but their ability on the ball too.
"Georgia looked very physical and looked hard to break down. But their number 10 looked a good passer and was able to spin the ball wide. They showed some good skills in the backs, so are capable of playing an open game too," said Wallace.
"The (Argentina-Georgia) game went as we thought it would. Argentina's fitness told in the end but if the Georgians had got lucky in the match, they might have been able to hold out for a little bit longer.
"It's going to be intense (on Saturday), so we'll have to play differently than how we played the other night. We'll have to hold onto the ball, try and break them down a lot more rather than trying to score tries from anywhere and everywhere. Or trying to make 30 metre breaks from first phase. We'll have to work a lot harder in grinding them down."
Wallace was "delighted to get though 70 minutes" of last weekend's victory over Namibia - his first appearance in an Ireland jersey since March.
"It was great to be back on the pitch. I had been worrying about making little errors because I hadn't played for so long," admitted the 31-year-old, who overcame a chronic ankle injury to make his World Cup debut.
"I would have liked to have been more involved in the game but that's the next phase. Hopefully I get more involved against Georgia."
The Georgians' display in their opening World Cup game showed just how difficult it will be for Ireland to qualify out of Pool D, and Wallace reckons hard work will be key if he and his team-mates are to keep on track to make the quarter-finals.
"I'm not sure what sort of team Georgia will put out as there's only a few days between games for them. They'll have taken great confidence from their first match and that will make them more dangerous against us.
"We would have preferred it had Argentina not got the bonus point from the match. Argentina will be in contention for winning the pool.
"It's not going to be an easy pool, that's for sure. Georgia have shown they haven't come here to make up the numbers, they won't lie down and be beaten. It means we'll have to work hard in every game," he added.