The Maroons were considered the biggest underdogs since 1995, but showed ridiculous fight to outlast the Blues 20-14 in a thrilling grandstand finish.
Wily coach Wayne Bennett's fingerprints were on everything as his team of rag-tag players sprung an almighty ambush against the odds.
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Bennett may have been the mastermind of the upset, but Cameron Munster was the executioner. For NSW, he was the grim reaper - wreaking havoc across the field.
Munster and debutant Harry Grant were the clear standouts for the Maroons - and another red-hot performance saw Munster awarded the Wally Lewis Medal as the player of the series despite being knocked unconscious and playing just two minutes in Game Two.
Queensland had to show incredible bravery to hold on in a wild final four minutes after the Maroons were reduced to 12 men following the sin-binning of fullback Corey Allan.
Their victory was tarnished somewhat by a final siren farce that saw NSW launch a referee challenge as Queensland players were already celebrating the famous win. It was even more perplexing when the NRL bunker announced the challenge was successful.
The Blues challenged a knock-on from Joseph Paulo, claiming the ball had been stripped - but replays showed the forward had simply lost possession as he tried to pass it.
Replays then showed Maroons hooker Jake Friend knocked the ball on as he tried to pick up Paulo's pass - which is the reason why the NSW challenge was successful - but because it wasn't a penalty, full time was called and the series was over.
The decision was finally reached after several dramatic minutes where both teams were left nervously waiting around on the field.
A worried Phil Gould declared the game was over despite the threat of another video referee blunder.
"It's all moot. He tries to pass it. He tries to pass it. Game over," Gould said before the bunker announced its decision.
"It's not going to make any difference because the clock's gone."
In the end, nothing could take the win away from the Maroons and when the dust settled they were eventually confirmed victors.
Sanity prevailed and the State of Origin Shield is Queensland's for another 12 months.
Despite the late drama, the Maroons were celebrating the sweetest of victories led by playmaking superstar Munster.
Earlier, in the first half, the game was turned on its head by the sickening moment Blues captain James Tedesco was knocked out cold.
It was just one of many hugely dramatic moments.
Here's how the drama unfolded.
Updates
There was huge drama on the final siren as Queensland players were celebrating a well-earned victory after a punishing final 10 minutes of desperate defence.
The Maroons had to defend countless repeat sets camped on their own try line, but refused to buckle under the charging NSW attack.
The Maroons were awarded the win 20-14, but only after a late referee challenge from NSW caused farcical scenes at full time.
The Blues challenged a knock-on from Joseph Paulo that ultimately ended the game. The Blues argued the ball had been stripped – but replays showed he had lost it cold as he hit the ground.
However, despite the clear replays, the video referee was heard saying that the NSW challenge had been successful because he judged Queensland star Jake Friend had knocked the ball on after Paulo's knock on.
The announcement left Paul Vautin and Phil Gould lost for words – but sanity eventually prevailed when full-time was blown as soon as the video referee announced his call.
Queensland debutant Corey Allan has been sent to the sin bin to set up a grandstand finish.
The moment came when Josh Addo-Carr was taken out by Maroons fullback Allan after he sprinted down the field to chase down a kick that went in behind the Queensland defensive line.
Addo-Carr then booted the ball ahead again, but was stopped by Allan in a clear professional foul.
After sending the matter to the video referee, Allan was given his marching orders.
It left Queensland with just 12 men on the field for the final four minutes of the game.
The Blues then crafted another repeat set when they forced a line drop out in the 79th minute.
The game was paused in the 76th minute as NSW medical staff assessed a distressed Cody Walker on the field after a head injury.
Walker was motionless on the ground after appearing to accidentally bump heads with a teammate.
Walker also suffered a head injury in Game 2 of the series.
He was eventually driven from the field on a medi-cab stretcher and was given an applause by the Queensland crowd.
Queensland winger Valentine Holmes has dropped a sitter on the wing with the try line begging.
Holmes dropped a pass from Corey Allan when he was unmarked near the try line.
NSW went up the other end and picked up a crucial penalty goal to further slash the Maroons' lead to 20-14 with just seven minutes to play.
NSW is coming home with a wet sail to set up a dramatic finish in the 2020 State of Origin series.
The Blues cut Queensland's lead back to 20-12 after Daniel Tupou finished off a nice move on the NSW left edge.
The winger found himself unmarked on the touch line after Clint Gutherson was given the ball with a defensive overlap.
He drew the defender and then sent Tupou over for the Blues' second try.
Queensland debutant Harry Grant has darted through three tacklers to put Queensland in a dominant position with 15 minutes left to play.
Grant picked up a loose pass from an offload 10m away from the try line and then ducked his head and squeezed between two defenders and reached out with a desperate lunge to score a critical try.
Grant's try came after he only entered the game from the interchange at the start of the second half – and immediately started cutting holes in the NSW defensive line.
His try made it 20-6.
NSW is hanging on by a thread in the second half with Queensland leaving the Blues' defence under the pump.
The Maroons finally had points to show for their field position dominance in the 59th minute when Valentine Holmes kicked a penalty goal to extend the home team's lead to 14-6 with 20 minutes left to play.
A wobbly Cameron Munster kick has given Queensland a 12-6 lead at half time after he caught the Blues' left edge defence desperately short of numbers.
Munster's kick landed in no-man's land, but debutant Edrick Lee still had enough time to pick up the loose ball and cut back inside of the sliding NSW defence.
The try followed a period of dominance for the Maroons after James Tedesco was forced from the field with a head injury.
The game was briefly delayed by a pitch invader in the first half.
"There's some idiot streaking, Queensland great Paul Vautin said. "No, he's got clothes on. A streaker in clothes."
The pitch invader was taken from the field by security.
Blues captain James Tedesco has tied the scores up after he found himself in the right place at the right time.
Tedesco dived on a loose ball after Daly Cherry-Evans and Corey Allan both spilled the ball on the try-line.
Allan dropped a kick from Nathan Cleary and it was Tedesco that reacted the quickest.
It left the game tied up at 6-6 after 18 minutes.
