Somerset's fast bowlers stole the show against Worcestershire to book their place in the Bob Willis Trophy final against Essex.
Worcestershire, 58-2 overnight, were finally bowled out for 184 - and all 10 wickets went to the opposition's pacemen.
That completed a haul of 90 wickets in five Trophy matches by Somerset's five fast bowlers, Craig Overton (28), Josh Davey (24), Jamie Overton (15 before his move, before the final game, to Surrey), Jack Brooks (13) and Lewis Gregory (10 in two games).
Only one was taken by a spinner, for Roelof van der Merwe, in their first game.
Somerset and Essex will meet in the five-day Lord's final, starting on 23 September.
Essex, the reigning county champions, saw their place assured late on the final afternoon of the final round of qualifying group fixtures when the England and Wales Cricket Board's technical committee officially declared Sunday's abandoned Gloucestershire-Northants game a draw.
Therefore, the deciding factor, if two of the three group winners tied on points, would still be 'most wins', as originally planned, and not 'run rates' as was briefly mooted the previous day, to cause a bit of unexpected confusion and delay.
Essex had more wins than Derbyshire, who could only equal the South Group winners' 90 points if they beat Lancashire in Liverpool. And, by then, it was already becoming clear that they would not.
In the end, Derbyshire lost by 130 runs and did not even finish top of North Group. That honour went to Yorkshire, who beat Leicestershire in Leeds, but only managed 87 points.
They finished with three fewer points and one win less than Essex and were left bemoaning their bad luck with the weather.
Having gone unbeaten in the group, after opening up with away wins against Durham and Nottinghamshire, Yorkshire then had successive rain-hit draws against Derbyshire and Lancashire.
"I feel we've played well enough to warrant getting to Lord's, but we've lost nearly 500 overs," said Tykes head coach Andrew Gale. "If we'd had good weather, who knows what would have happened."
Yorkshire topped North Group thanks to that defeat for Derbyshire by Lancashire, while the Tykes completed their expected win over Leicestershire shortly after lunch thanks to young seamer Jordan Thompson's maiden five-wicket haul.
The Foxes, trailing by 50 overnight on 78-5, did at least make Yorkshire bat again, being eventually bowled out for 161. But that left only 34 to win - and Adam Lyth and Tom Kohler-Cadmore took just 38 balls to complete a 10-wicket victory.
As for Derbyshire, a week which began with the unfancied East Midlanders as North Group leaders chasing a first Lord's final in 22 years ended in disappointment.
Just as Lancashire beat them in the rain-hit 1998 NatWest Trophy final at Lord's, it was the Red Rose who denied them again, this time in front of a lot less people, although in the presence of a splendid pavilion at Aigburth.
The narrow failure to earn any batting bonus points on day three had already cost them, but salt was rubbed into that wound when Derbyshire fell well short of their victory target of 381, bowled out by the young Lancashire attack in bright afternoon sunshine on the banks of the Mersey for 205.
The bottom of the table battle ended in a draw, with both Nottinghamshire and Durham still winless largely due to a final-day half century from Michael Jones (82) and a 45-run last-wicket stand between Brydon Carse and Ben Raine.
Durham were eventually bowled out for 329, setting Notts 202 to win in an hour, with Peter Trego and Ben Duckett opening the batting. But, shortly after Trego had departed for 34, including three fours and two sixes, off 22 balls, they called off the hunt at 82-1 in the 10th over.
While the Somerset seamers booked that trip to Lord's, the real matchwinner in that 60-run victory over Worcestershire was opening batsman Tom Lammonby, in carrying his bat for a second-innings century - scoring 107 out his side's 193 runs.
It was a second ton in only his fifth first-class match for a player who had not made his debut when this season made its late start on 1 August.
"Tom Lammonby's hundred was right up there with any first-class hundred I've seen," said Worcestershire coach Alex Gidman. "It was an outstanding innings, probably the difference in the game."
"We wouldn't have been in the position without Lammers," said Somerset captain Tom Abell. "To play with that temperament and skill, when there were wickets falling all around him, I can't speak highly enough of it. An innings far beyond his years."
In the other Central Group game, Warwickshire and England batsman Ian Bell got a nice ovation and a guard of honour from players on both sides as, having failed to record a farewell century the previous day, he duly completed his first-class career at Sophia Gardens, Cardiff.
It was a disappointing end as the Glamorgan last pair hung on for a draw to leave both sides still winless but the Bears in third place behind the Midlands neighbours.
Surrey finally completed their first victory of the Bob Willis Trophy campaign at the final attempt as they took a couple of sessions to finish off Sussex by six wickets at The Oval.
In the day's only remaining game in South Group, after wins for table-topping Essex against Middlesex and second-placed Kent against Hampshire the previous day, it also allowed Surrey to lever their way off the foot of the table and leave Sussex in bottom spot.
It made it a sad end, at least as far as his red-ball leadership is concerned, of outgoing South Australia-bound coach Jason Gillespie's time in charge of Sussex.
Resuming on 109-9 after being undone by Surrey spinners Dan Moriarty and Amar Virdi the previous evening, Sussex reached 128, thanks to Stuart Meaker's defiant 42 against his former county.
But England Test opener Rory Burns followed up his first innings hundred with 52 as Surrey chased down 156 to win on a turning pitch, although not before a little late drama when 16-year-old debutant James Coles - Sussex's youngest first-class cricketer - dismissed Jamie Smith and Burns in the space of four balls.