Hampshire 181 for 5 (McDermott 64, Vince 41, Prest 41) beat Essex 174 for 7 (Allison 69*, Benkenstein 54, Turner 4-23) by seven runs
Hampshire Hawks fast bowler John Turner's best T20 figures knocked Essex out of the Vitality Blast.
The Eagles, who were losing finalists in 2023, only needed a point at Utilita Bowl to overtake Gloucestershire into fourth but were undone by Turner's 4 for 23.
Ben McDermott's exquisite 64, together with 41s for James Vince and Tom Prest got Hawks to a defendable 181.
Essex looked out of it at 58 for 5 but teenagers Luc Benkenstein and Charlie Allison crashed maiden T20 half-centuries in an 86-run stand.
Turner's return at the death ended their hopes of a quarter-final place as Hawks secured a fourth win of an otherwise poor competition by seven runs.
Vince and McDermott got Hawks off to a flyer after being stuck in, as the opening partnership finally clicked in 2024 to put on a highest first-wicket stand of 97.
Before this innings, Australian McDermott had only scored 173 runs across this season's Blast but came alive with a mix of the brutal and inventive for a 39-ball fifty - his 10th across three seasons at Hampshire.
Vince fell nine short of following McDermott to the milestone when Benkenstein bowled him, but Prest entered to thump Paul Walter for 18 off an over.
The Hawks were on for 200, but Shane Snater put a spanner in the works with a double-wicket over in the 16th - which saw the back of McDermott for 64 and Benny Howell.
Two overs later, Walter ended Prest's sensational 21-ball knock before Liam Dawson identically pulled to deep fine leg.
Joe Weatherley and Toby Albert bashed 25 off the final two overs to drag the hosts to a total Essex would have felt comfortable chasing.
However, things never got going, especially when Adam Rossington tickled the first ball of the innings behind before Chris Wood also found Dean Elgar edging to snare two wickets in the first over of the reply.
Wood passed the flame to Turner - who also began with two wickets in an over.
Michael Pepper skied a caught and bowled, Walter pulled to short third before Matt Critchley gave Turner figures of 3 for 6 after two overs.
A rescue act was needed for Essex, and two 19-year-olds stepped up.
Benkenstein had already almost single-handedly beaten Glamorgan during a collapse earlier in the season but it was Allison who took control.
His whipped six and hammering over long on were the stands out from a 37-ball fifty - his first in T20s having only previously had 50 runs to his name.
Benkenstein also reached his maiden format half-century - four balls quicker than his contemporary - as the partnership extended to 86.
But with 38 required off 18, Benkenstein scooped straight up to end his fun before Turner clean-bowled Harmer for his fourth.
Turner's penultimate over only went for six, which left 15 needed off the last, which Wood defended brilliantly - despite Allison ending up on a valiant 69.
