The Blues are 1-0 up in the best-of-three series following a heroic come-from-behind 22-20 win in the Origin opener at Accor Stadium on Wednesday night.
But NSW were on the ropes after 20 minutes, down 20-0 thanks to their own yardage errors and some brilliance from Maroons rookie Sam Walker.
When Hamiso Tabuai-Fidow waltzed in for Queensland's third try, the Blues were completing at 57 per cent and had not yet played the ball in the visitors' red zone.
Starting props Addin Fonua-Blake and Mitch Barnett combined for just 33 metres in their first stints, and even the ultra-reliable Brian To'o made three first-half errors out of yardage.
NSW had been here before; they have now lost their last three first halves by a combined total of 66-12.
"We didn't play well in the first half at all. Never really gave ourselves a chance," said coach Laurie Daley.
But the game turned on its head midway through the second half, when Maroons fullback Kalyn Ponga shoulder charged Tolu Koula and became the seventh Origin player sent from the field.
The dramatic mishap brought Penrith young gun Casey McLean into the fray for an Origin debut on the left wing, and opened the door for a Blues comeback.
NSW were back in the fight when McLean soared high to take a Walker bomb in yardage and kick off a counterattack.
Moments later, fellow first-gamer Ethan Strange was opening up a gap on the left and finding Stephen Crichton, who passed inside for Strange to score on debut.
Suddenly, the Blues were daring to dream.
McLean almost had a try of his own when he grabbed a waving Nathan Cleary kick but passed back to Crichton instead of barging through what appeared a hole.
A Cleary 40/20 kick put NSW in position for another chance and it was another debutant in Blayke Brailey who threw a flat ball for the halfback to score.
In the pouring rain and with the Blues' last roll of the dice, Cleary - so often under fire for his record in Origin - had the footy in his hands.
His bomb sailed up for a determined James Tedesco, who reefed the ball away from Selwyn Cobbo and slid over for the match-winner.
The veteran Blues fullback, who earned a fairytale recall for Origin I, would surely have known it was the young stars around him who made it all possible.
"I thought all our guys actually lifted, and they needed to," Daley said.
"Origin is all about fight, isn't it? You're never going to get too many opportunities to put on plays that look good, which you might do in the NRL.
"It's about fight, it's about hunger and it's about having a crack."