Samoa centre Stephen Crichton kicked a field goal in golden point extra-time to seal a 27-26 win for his country as they became the first tier-two nation to advance into a Rugby League World Cup final.
The Samoans will play Australia at Old Trafford next Saturday (Sunday AEDT) after exacting revenge on an England side who had beaten them 60-6 in the opening game of the tournament.
It took until the 84th minute for a winner to be found, Crichton stepping up to the plate after Anthony Milford's earlier attempt had been charged down.
Samoa coach Matt Parish has boasted how his side would build coherency throughout the tournament and they looked a class above an England that had seemingly rolled up expecting the same result.
It was the first time the English had been scrutinised in this tournament and their panache and fight went out of them.
It wasn't until England were 20-12 down with 15 minutes to go that they snapped into life and head coach Shaun Wane must be left wondering how his side failed to show up at London's Emirates Stadium.
Next week could be challenging for the Samoans given their Junior Paulo, who had a striking charge thrown out to play in this game, is likely to face suspension for a spear tackle on Tom Burgess.
In front of a 40, 489 strong crowd, Samoa came to shock the English.
Centre Tim Lafai gave them an early when he sidestepped Kallum Watkins after five minutes.
While Elliot Whitehead hit back for England, Ligi Sao put Samoa in the box seat at half-time with a 10-6 lead.
England were clinging on and they got a dose of luck after the break when Lafai fumbled the ball on his own early in the second for John Bateman to touch down.
There was a hope England might have turned the corner with Wane's half-time talk still ringing in their ears but Samoa quickly responded twice through Lafai and Crichton.
Only a bustling Herbie Farnworth try - where he beat six defenders to score - brought the English back into contention and the home crowd to life.
Winger Tommy Makinson added the conversion and soon had to add a penalty from right in front when Paulo took out England skipper Sam Tomkins while he kicked the ball.
It was 20-20 with seven minutes left when Victor Radley threw a speculative pass out wide, only for Crichton to intercept and run in from 50 metres out.
That looked to have given Samoa the winner but then Farnworth added a second in the 77th minute.
Makinson converted to send the game to golden-point and when Tomkins made an error in England's half, Crichton stepped back into the pocket and notched his field goal.