Harlequins staged the greatest comeback in Premiership history to book a Grand Final date with champions Exeter.
The Londoners, 28-0 down inside half an hour, came back from the dead with five unanswered tries to force extra-time at Ashton Gate.
They then completed the job with Tyrone Green and Joe Marchant scoring as Quins broke Bristol hearts to become the first away team for six years to win a play-off semi-final.
Quins legend Ugo Monye hailed the epic contest as "one of the most remarkable 104 minutes of rugby I‘ve ever seen in my life.”
Man of the match Green agreed: “That was the most crazy game I’ve ever been a part of - and the best.”
Bristol had led the league since round six and arrived at Ashton Gate supercharged, challenged by boss Pat Lam to not be satisfied with finishing the regular season on top.
For 28 minutes they rampaged, scoring a point a minute, dazzling and devastating in equal measure. Quins were caught in the eye of a hurricane.
Ben Earl plundered the opening try and England team mate Max Malins quickly added two more on a day he would claim only the third hat-trick in play-off history.
When Luke Morahan bagged a fourth Quins were staring humiliation square in the face.
They couldn’t catch a break. Aaron Morris pulled a hamstring kicking the ball. Louis Lynagh scored only to have it chalked off for a foot in touch.
But then, finally, Bristol made a mistake. Malins dropped a high ball, Alex Dombrandt picked up and ran it in. A ray of light pierced their darkness.
Lam’s men really shouldn’t have been blinded by it yet they were. The team that left for half-time was not the one that returned.
In the away changing room Quins were calm. “Our message to the boys was ‘stay in the fight, give yourselves a chance’,” manager Billy Millard said.
Within two minutes of the restart they scored again, Green going over after razor sharp thinking by Marcus Smith and Danny Care.
James Chisholm came off the bench to claim a third and before Bristol could get a handle on the unfolding calamity the impressive Lynagh made it four.
Now Bristol were clinging on for dear life as the turning tide dragged them away from their dream - and five minutes from time Marchant scored to force extra time.
There was only ever going to be one winner from there and a try in each half by Green and Marchant sparked wild celebrations amongst the history-makers.
“Sport is about emotion,” said watching World Cup winner Lawrence Dallaglio. “It’s about love, it’s about hate and every emotion in between.
“At half time we had two emotions: agony and ecstasy. We had one team that was just so far out in front that you worried for Harlequins they might be humiliated.
“I can’t say enough about Harlequins. When you’re dead and buried at half-time and you come back from behind like that, it’s extraordinary.”
BRISTOL - Tries: Earl, Malins 3, Morahan. Con: Sheedy. Pens: Sheedy 3, .
QUINS - Tries: Dombrandt, Green 2, Chisholm, Lynagh, Marchant 2. Cons: Smith 4.
