Defeat was staring the 39-year-old Crafty Cockney in the face when he trailed 2-3 and lost the opening leg of the sixth set. Amazingly Bristow won the next eight legs to lead 4-3 in sets and go one leg from victory.
Warriner, from Lancaster, stopped the rot by winning the next leg but Bristow took the next to gain an historic win after 108 minutes play.
Bristow's wish of playing the favourite Phil Taylor in the semi-finals tonight has been granted and he will now be trying to stop Taylor winning his fifth world title.
Bristow won a record five Embassy world championships in the 1980s and was runner-up five times. But since breaking away with the World Darts Council in 1993, he has fallen on hard times.
Even though he was not among the eight seeds, he proved that he is back in the big time and said: "Everyone is frightened of Phil Taylor. But I'm not frightened of him. I came down here to win the title and stop Phil equalling my record.
"Phil played great to beat Keith Deller 5-1 in his quarter-final but it will be different tomorrow. However, I agree that in the last 18 months Phil has played marvellous darts. If he lost four stone and smartened himself up a bit he would be alright!"
n The Embassy World Darts Championship begins at the Lakeside Country Club, Frimley Green, today, with the 40-year-old Martin Adams aiming to justify his top seeding.Reuse content