Samoa's Stephen Crichton hit an extra-time drop-goal to seal a 27-26 victory over England on Saturday and book a first-ever Rugby League World Cup final berth against reigning champions Australia.
A gripping game saw the two sides level 26-26 at the regulation-time whistle at Arsenal's Emirates Stadium thanks to a late Herbie Farnworth try for England converted by Tommy Makinson.
Samoa, beaten 60-6 by England in the tournament opener, held their nerve in extra-time, Crichton popping over the crucial 'golden-point' drop-goal.
It means that for the first time a nation that isn't Australia, New Zealand, England/Great Britain or France has reached a World Cup final.
Australia booked their berth in the final, next Saturday at Manchester's Old Trafford, with an equally enthralling 16-14 victory over New Zealand in Leeds on Friday.
"I don't think anyone gave us a chance tonight but the belief we have is very strong," said man-of-the-match Samoan stand-off Jarome Luai said.
"The (tournament-opening) loss was a blessing in disguise but we put our heads down and we worked hard."
England coach Shaun Wane added: "They had better composure. We were just not good enough and on the biggest stage possible."
Samoa shocked the tournament hosts with the opening score, Joseph Suaali'i sucking in defenders with a half break in the middle to open a chink of light out wide for centre Tim Lafai to glide past a flat-footed Kallum Watkins to cross.
Crichton missed the conversion, but the Samoans, with skipper Junior Paulo at his barn-storming best in both defence and attack, were in the ascendancy in front of 40,489 fans.
But Paulo was sin binned for a tip tackle on Tom Burgess, swiftly followed by a head injury as Fa'amanu Brown was laid out cold after a Tommy Makinson charge.
England opened their account after half-back George Williams stepped inside a couple of defenders and offloaded to Elliott Whitehead for a simple try. Makinson converted.
Ligi Sao restored the Samoan lead, spotting Watkins on his heels and immediately attacking the blindside.
The Hull prop allied his quick thinking with strength as he rode Dom Young's challenge and took the winger with him as he slid across the line for a try. Crichton converted to hand Samoa a 10-6 half-time lead.
- 'Quickfire try' -
England opened the second period with Bateman pouncing on a loose ball after Lafai failed to deal with a Williams kick under pressure from Watkins.
Makinson converted, but Samoa responded with one of the tries of the tournament.
On the fifth tackle, Luai opted not to kick, instead jinking his way across the England defensive line before finding Paulo on the crashball.
The giant prop was brought down close to a post but somehow popped the ball back, Luai volley-balled a pass on to Crichton, who crossed for a try he also converted.
Young then spilled a simple Luai kick deep in English territory. Samoa made no mistake with their attacking position, Crichton, the Penrith Panthers stand-off, easily stepping Young's blitz defence to find Lafai for his second try.
England tried to respond, leading to a last quarter of harum scarum rugby.
The ball was whipped left again before Farnworth bundled his way through six would-be defenders for a fine individual try.
Makinson converted to make it a two-point game with 14 minutes to play and soon after drew the scores level at 20 apiece after Paulo, the Samoan skipper, needlessly took out counterpart Sam Tomkins late.
But, as England attacked, Crichton picked off an interception and sprinted in for his second try, converting to make it 26-20 with five to play.
Farnworth made sure the game went to extra-time as Williams broke and Whitehead played the centre in from 50 metres, Makinson hitting the crucial conversion.
In extra time, Anthony Milford had a snap drop-goal charged down, but then Crichton, deeper in the pocket, made no mistake to seal a famous victory.