The Blaze have qualified for Finals Day after winning their seventh successive Charlotte Edwards Cup match of the ongoing campaign, by 13 runs against Northern Diamonds at Headingley.
The Blaze, who defended a 160-target, are the runaway leaders at the top of the table but were threatened by a Diamonds side, led by Bess Heath's 32-ball 59.
International pair Kathryn Bryce and Tammy Beaumont underpinned their side’s 159-7 with impressive scores of 54 off 39 balls and 45 off 33 respectively.
Heath then crashed a half century with Sterre Kalis offering support, but the hosts fell from 94-2 in the 12th over to 146 all out in the 20th.
England leg-spinner Sarah Glenn claimed 3-32 and Bryce continued her excellent day by removing Heath caught at deep cover as one of two wickets with her seamers.
After the early departure of Teresa Graves, stumped off the impressive off-spin of Erin Burns - she returned 3-19 - Scot Bryce and England opener Beaumont shared a blistering second-wicket 78 inside eight overs to advance Blaze from 11-1 in the third over having been inserted.
Both hit sixes down the ground, Beaumont’s arrow straight one off the seam of Rachel Slater, in particular, lighting up a grey Headingley day.
The start of play was delayed by 15 minutes because of rain, while a minute’s silence in memory of local Rugby League legend Rob Burrow was observed.
After Beaumont fell, caught at short fine-leg trying to sweep Sophia Turner’s seam - 89 for two in the 10th over, Diamonds did fight back admirably.
All-rounder Burns helped off-spinner Katherine Fraser remove Sarah Bryce with a catch at mid-off before bowling her fellow Australian all-rounder Heather Graham.
Wickets continued to fall. Bryce, having reached a dynamic fifty off 34 balls, was one of them.
She reverse swept leg-spinner Katie Levick to short third, the first of two wickets in the 17th over as Ella Claridge was bowled - 139-6.
Burns had Glenn well caught at long-on by Lauren Winfield-Hill in the Blaze’s search for late runs.
When new ball seamer Grace Ballinger had Winfield-Hill caught at cover and England leg-spinner Glenn bowled Hollie Armitage, leaving Diamonds at 18-2 in the third over, it seemed like a forlorn task for the hosts.
But England wicketkeeper-batter Heath had other ideas, crashing five of her first 11 balls to the boundary.
She hit 10 fours in her fifty off 28 balls, with her switch hit on show alongside brute power.
However, just when the Diamonds were on the charge, things changed again.
Kalis fell caught behind off Glenn, and Heath was caught at deep cover off Kathryn Bryce, as two of four wickets to fall for 26.