It took a decisive late contribution from Leon Pryce to take St Helens into territory where only Wigan had trod before by winning a third Challenge Cup in a row.
Pryce might have had a quiet afternoon at Wembley overall – a tribute to the diligent job Hull did on him – but he was there when it counted to complete the match-winning flourishes.
Hull had just taken the lead for the one and only time in the game when he struck first, bending the defensive line in that distinctive way of his and getting his arms free to serve up the pass for Francis Meli to score. Hull had been in front for just two minutes.
Finally, after Gareth Raynor had again put the courageous underdogs in with a chance, Pryce killed them off by going through for a try of his own – his first in a Challenge Cup final.
"I will cherish that moment," he said. "To win three Challenge Cup finals, that's something that might not happen again, with the strength of the competition. It's not like Wigan's day."
Saints' neighbours won eight off the reel from 1988 to 1995 and no one is suggesting that Saints are going to emulate that. There was an undeniable feeling after their latest victory, however, that it is going to take something very special to break their sequence and that, at the moment, they are the club with the trump card up their sleeve.
On Saturday, they included Pryce, who underlined how important it is for England's chances in the World Cup that the assault charges he faces do not prevent him travelling to Australia.
They also included Paul Wellens, who won a tight vote for the Lance Todd trophy for a typically resourceful performance, and Meli, who played one of his best games for Saints with two tries and other good work.
Memorable for the wrong reason was the cameo appearance of Paul Sculthorpe, who suffered the sickening experience of dislocating his shoulder with his first tackle of the match.
After all his other injuries, the former Great Britain captain was desperate to go out with a reminder of his qualities. Instead, all he demonstrated was that if it is not one thing going on him, it's another.
Even in their hour of triumph, his team-mates' sympathies were with him and, in the longer term, the odds against any club taking a risk on him have obviously widened. He deserved better than to go down as a player whose club career at Wembley amounted to one minute.
Hull had their heroes too on a day that recaptured many of the final's best traditions on its historic stage. Richard Horne, looking gaunt and fragile, at least by rugby league standards, after five months out with a neck injury that threatened his career, was thrown into the action after only 15 minutes with his side already 10 points down. The first thing that hit him was a perfectly fair but brutally hard tackle from James Graham, which hammered him into the ground on the top of his back.
Horne himself reckoned it was the best thing that could have happened to him. "When you get hit by a shot like that and you get up, you know you're all right," he said.
That is the philosophy of a brave man and that was the way he played. Not that he was on his own; others like the potentially Saints-bound Garreth Carvell had big games. In fact, it was hard to fault the attitude of any Hull player.
They might have been unimpressive in their Super League campaign and unfancied for this game, but they did so much to turn it into a memorable final.
Admittedly, as Saints' Jon Wilkin said, there could have been 20 or 30 points between the teams at half-time, but having limited the damage to 10, the outsiders stormed back stirringly.
Kirk Yeaman had a distinctly mixed game, but he made a name for himself with the two tries that put them ahead. "But we needed to hang on to that lead for more than two minutes," said his coach, Richard Agar.
He can be proud of his team's spirit and determination, while Saints' Daniel Anderson can be proud of his whole three and a half years in charge, shortly to come to an end.
Even in victory, his mind was focusing on the next game, this Friday against Wigan. There is no word in his vocabulary for having won enough. Saints' players are, however, being treated to a break in Madrid to help them prepare for the play-offs.
They did not look in need of much rest and recuperation on Saturday, even in temperatures more appropriate to a Spanish summer. Anyone standing between them and the double of the Challenge Cup and Super League title can expect, at some stage in the proceedings, to have the heat turned up on them.
Hull: Byrne; Sing, G Horne, Yeaman, Raynor; Washbrook, Lee; Dowes, Berrigan, Cusack, Manu, Tickle, Radford. Substitutes used: R Horne, Carvell, Briscoe, Thackray.
St Helens: Wellens; Gardner, Gidley, Talau, Meli; Pryce, Long; Hargreaves, Cunningham, Graham, Wilkin, Flannery, Sculthorpe. Substitutes used: Gilmour, Roby, Clough, Fa'asavalu.
Referee: S Ganson (St Helens).Reuse content