The Hampshire Academy pulled off arguably their best win since they joined the Premier set when they beat Havant, the defending champions, by 70 runs on a strip that favoured the spin bowlers the longer the match went on.
Indeed, the slow bowlers captured 14 of the 18 wickets that fell during the day's play - Charlie van der Gucht (4-41) and Mitchell Stokes (3-36) producing telling performances after leggie Ian Hilsum had removed two of Havant's top guns.
The result was a massive setback to Havant's already slim chances of retaining the title, but a real feather in the cap of the Young Hawks who thoroughly deserved their win.
Havant were, though, without broken-fingers victim Richard Hindley, the wounded hero of Hampshire's County Championship victory over Glamorgan.
Hindley spent a bizarre day signing autographs and doing radio interviews - though he would have much preferred to be in the thick of the action !
Put into bat on a softish surface, the Academy began positively with a 52-run partnership between Peter Hammond (31) and Alex Richardson who, along with Hawks skipper Alex Morris, both departed inside three overs.
Hampshire team manager Paul Terry watched boundary-side as Tom Burrows (45) and Kevin Latouf (27) batted sensibly to see the Academy through to lunch at 108-3.
But, as early as the 37th over interval, Havant were beginning to concern themselves at the help their own slow men were getting.
Latouf was well taken down the leg-side by Steve Snell, while Burrows became the first of three victims for Phil Loat within five runs of a deserved half-century.
Stokes (18) struck several meaty blows but, when the Academy dipped to 183-8, Havant fancied their chances of wrapping up the tail.
Talented Shanklin teenager David Griffiths had other ideas, striking a series of terrific shots, including two huge sixes over mid-wicket, in an undefeated 35 that wrested the initiative away from Havant and put the youngsters in the driving seat.
But Griffiths did not bowl as well, suffering at the hands of fellow Islander Snell as Havant, despite losing two early wickets, quickly posted 53-2.
Academy coaches Tony Middleton and Giles White looked on with anguish as Havant feasted on several overs of indifferent and mediocre bowling.
But, having reached 87-2, Havant lost their way - and their wickets - with the off-spin of Stokes proving hugely effective.
Van der Gucht appeared to be struggling to land the ball in the right area - but the left-arm spinner, who has fought back so courageously from the serious injuries he sustained in a road traffic accident almost two years ago, was later to strike a series of crucial blows.
Struggling against the turning ball, Havant plunged from 87-2 to 114-6 before losing their last four wickets - three of them to Van der Gucht - for just eight runs. They were 154 all out.