Wallace had a hand in each of the Broncos' three tries and also landed four goals, two from penalties, as Brisbane overcame a 14-8 halftime deficit to claim a gutsy victory over the tricolours.
But the win may come at a cost with fullback Karmichael Hunt placed on report for an ugly shoulder charge on a slipping Braith Anasta in the 18th minute which left the Roosters five-eighth with a badly broken nose.
Anasta returned to the field in the second half with his snout heavily strapped, but the bleeding continued throughout the game and he was finally sent from the field in the 77th minute with claret running down his face.
With skipper Darren Lockyer again starting off the bench, Wallace took immediate control of the Broncos, with his grubber in the third minute fumbled by Craig Fitzgibbon and falling to David Stagg to score the first points of the game.
Former Penrith halfback Wallace was in everything for the Broncos and it was his deft inside pass to rampaging Tonie Carroll just five minutes after the break which levelled the scores at 14-all.
Wallace booted the Broncos ahead 16-14 with a 20m penalty goal in the 51st minute after Roosters winger Shaun Kenny-Dowall ran behind Anasta in a blatant shepherd on his return from a deep Wallace kick.
Wallace, 22, provided another pinpoint kick moments later and winger Darius Boyd won the foot race against Anthony Minichiello to narrowly ground the ball as the Roosters fullback tried to boot it away.
For a team which has lacked a quality halfback for several seasons, the early form of Wallace will come as a welcome addition and add to the premiership expectations for the 2006 premiers.
And Wallace wasn't just thriving in attack, pulling off an excellent diving cover tackle from behind on Willie Mason 10 minutes before fulltime as the rampaging prop was charging toward the tryline with only Hunt to beat.
The Roosters piled on plenty of late pressure, but Kenny-Dowall was denied their only real chance when he was ruled to have stood on the touchline before grounding the ball in the corner in the 71st minute.
Lockyer had two missed field goal attempts in the final five minutes as he tried to seal the result.
Broncos coach Wayne Bennett however said Wallace still has plenty of improvement left after his first two appearances for the club.
"There are aspects he can do a lot better," said Bennett.
"He has a lot more to offer the team than he is showing us at the moment."
Roosters coach Brad Fittler was confused about the controversial first half no try ruling against Kenny-Dowall for an obstruction by Mitch Aubusson, with Bennett and Broncos skipper Darren Lockyer both agreeing the opposition was robbed a certain four-pointer.
"I'm just no sure of the ruling," said Fittler.
"I think sometimes we make it look so easy they think it must be illegal."
Fittler and Anasta both had no concerns over the high shoulder charge that knocked the five-eighth out briefly, with Anasta's nose still bleeding more than half an hour after the game.
"I cannot remember it, but everyone told me I slipped into it a bit," said Anasta.
"(Hunt) was very apologetic and I have no worries with (the tackle) at all.
"All I know is I have a lot of respect for him for apologising."