Western Storm 142 for 7 (Knight 66, Corney 46, Munro 4-23) beat Sunrisers 131 for 9 (Grewcock 40) by 11 runs
Heather Knight got herself into form ahead of England's series with New Zealand with 66 as Western Storm condemned Sunrisers to the wooden spoon in the Charlotte Edwards Cup.
England skipper Knight grabbed her second fifty in a row to average 52 in the competition, to put the disappointing Pakistan T20Is behind her before the White Ferns arrive for three ODIs and five T20s from next Wednesday.
Her 74-run stand with 20-year-old Emma Corney - who made a CEC best of 46 - put Storm on track for 142 for seven, with Blaze loanee Sophie Munro picking up four for 23.
Despite Grace Scrivens and Jo Gardner's speedy start, Sunrisers fell 11 runs short to end as the bottom-placed side for the fourth year in a row - with Storm ending their tournament a point and a place better off.
Storm chose to bat, and used Corney as a facilitator for Dani Gibson and then Knight to score runs quickly at the other end.
Gibson used her feet to good effect as she bashed a trio of boundaries before top-edging to short fine, with the visitors reaching a creditable 44 for one in the powerplay.
While Corney confidently ticked the runs along from one end, Knight showed all her experience and skill - with the pair putting on 74 for the second wicket.
Devon-raised Corney strode past her previous CEC best of 40 - but fell four runs short of a maiden fifty when she slapped to backward point.
It began a Storm collapse, which saw them lose six wickets for 41 runs in the final six overs.
Fran Wilson was run out by a sensational direct hit from the boundary from Gardner, Sophie Luff chipped to mid-off, Kate Coppack brilliantly pouched Amanda Jade Wellington at short third before Nat Wraith skied one.
But throughout, Knight continued to score at a decent pace, slog-sweeping the only six of the innings, as she brought up back-to-back fifties in 34 balls.
She was stumped off the final ball - to hand Munro the fourth of her impressive haul - as Storm reached 142 for seven.
In reply, Mady Villiers holed out to deep square in the fourth over, but Grace Scrivens and Gardner blitzed Sunrisers ahead of the rate.
But the duo fell within six balls of each other either side of the powerplay to begin a wobble they never recovered from.
Scrivens had continued her form from the 42 versus Blaze and unbeaten 62 against Stars to crash a quick-fire 26 - before falling to the last ball of the powerplay - while Gardner distributed three consecutive fours off Gibson.
But both offered up simple catches, before Lissy MacLeod was caught and bowled first ball by Chloe Skelton.
Amara Carr swept to short fine, Flo Miller was bowled and Amu Surenkumar found deep midwicket as Sunrisers never recovered.
Jodi Grewcock held firm with 40 - one of two run outs in the last over - but Storm completed their second win of the competition without further anxiety.
