Essex 163-9 (Heap 37, Scrivens 32, Gardner 30, Dean 3-36) beat Somerset 122 (Hazell 37*) by 41 runs.
Liberty Heap top-scored with 37 as Essex completed their Vitality Blast campaign with a comprehensive 41-run victory over Somerset at the Cooper Associates Ground, Taunton.
Somerset spinner Charlie Dean claimed 3-36, but Grace Scrivens and Jo Gardner weighed in with 32 and 30 respectively as Essex ran up an imposing 163-9 after winning the toss.
Seamers Katie Coppack (2-20) and Eva Gray (2-11) then put the skids under Somerset’s batting as the home side were shot out for an inadequate 122.
Neither side was able to qualify for finals day, but Essex leapfrogged Somerset to finish in fifth place, courtesy of their sixth win of the season.
Essex elected to bat and subsided to 58-3 in eight overs.
Alex Griffiths had Anneke Bosch held at deep mid-wicket and Sophia Smale fell to Chloe Skelton in identical fashion as Somerset made early inroads.
Dropped by wicketkeeper Jess Hazell off the bowling of Skelton, Scrivens made good on her escape to raise 32 from 25 balls with 5 fours in a productive powerplay that yielded 53 runs.
But her luck ran out when she was brilliantly run out by Liv Barnes.
Required to rebuild, Jodi Grewcock and Heap responded positively, the fourth wicket pair adding 44 in 5.2 overs to bring up three figures.
That was the cue for Barnes to strike another telling blow, the slow left-armer bowling Grewcock for 19 with the score 102-4 in the fourteenth.
Gardner demonstrated aggressive intent, smiting Barnes for a straight six, and then repeating the feat at the expense of Harris as she raised a quickfire 30 from 17 balls.
Harris had the last laugh, though, persuading Gardner to drive to extra cover.
But Heap remained at large, hoisting Dean for a huge six over deep mid-wicket before top-edging a catch to third man, having hauled her side to a competitive total.
That total appeared more handy still when Somerset lost three wickets in the powerplay.
Katie Coppack had Bex Odgers held at mid-wicket and Niamh Holland caught behind in a new ball burst of 2-15 from three overs, while Sophie Luff lobbed a Smale full toss to mid-on as the home side slipped to 29-3.
Making her final appearance of the season before returning to Australia, Anika Learoyd joined forces with Griffiths in an attempt to keep the chase afloat.
By the time Griffiths fell lbw to Eva Gray for 15, Somerset were 49-4 in the tenth and required to score at just under eleven an over.
Their task became even more difficult when Gray had Learoyd caught at long-on and then ran out Dean to reduce the home side to 50-6.
Skelton was then run out by Heap as things went from bad to worse for the home side.
Hazell mustered dogged resistance in a losing cause thereafter, raising 37 from 28 balls.
But it was too little too late.
Somerset captain Sophie Luff said: "That was not how we wanted to finish the competition and there may have been a bit of a hangover after losing to The Blaze the other day.
"Whatever the reason (for this defeat), it would be remiss not to look at the season as a whole and acknowledge the strides we have made in this format.
"To still be in with a chance of qualifying for Finals Day with two games left says a lot about this group and shows how much we have improved.
"We are bitterly disappointed by the manner of this defeat and there are some tired bodies around.
"When you have momentum in the Blast, you can ride the wave, but when it's against you, it's hard to get back up.
"Our batting has probably held us together a lot of the time and our top four have been superb.
"But there is a lot of work still to be done with our bowling attack and there is so much room for growth going forward."
Essex captain Grace Scrivens said: "I'm disappointed that we've not been able to make it to Finals Day, but this season has been much better than the last for us.
"There has been a pleasing progression in the way we have played our cricket, especially in the last couple of games.
"This was a convincing win and, hopefully, it will give us momentum going into next year.
"There was a bit of turn and a bit in it for the bowler, but it was a decent pitch overall to bat on.
"Nobody scored 50, but there were some nice partnerships out there and some key cameos, which was nice to see.
"Our plan was to kill the game off early and the seamers bowled nicely up top.
"It was a case of taking early wickets up top and then controlling things from there.
"It shows we are moving in the right direction."
