The Blaze qualified for the Charlotte Edwards Cup final with a thumping 84-run victory over winless Sunrisers.
England all-rounder Nat Sciver-Brunt continued her fine form as her 58, along with contributions from Tammy Beaumont (41) and Sarah Glenn (43 not out), helped Blaze to 198-6.
Sunrisers were never in the chase as they were bowled out for 114 with Sciver-Brunt one of four bowlers to take two wickets.
The Blaze, who have won all six of their matches in the 20-over competition, go straight through to the final at New Road on 10 June as group winners.
Elsewhere, defending champions Southern Vipers fought back superbly to beat Northern Diamonds by 16 runs and climb above them in the group into second.
Victory for Diamonds would have got them through to the semi-final but they can still qualify if they avoid defeat by Thunder in their final game on Wednesday.
The teams that finish second and third in the group will contest the semi-final with the winner meeting The Blaze in the final after.
After electing to bat Vipers recovered from 92-6 to post 144-6 thanks to an unbeaten 42 from captain Georgia Adams and 32 not out from 19 balls by Nancy Harman.
Former England seamer Anya Shrubsole (4-18) then removed Diamonds’ top three in her first two overs to leave them 5-3 and another clatter of wickets after they had recovered to 99-4 saw them fall short on 128-9.
Thunder kept their hopes of making the semi-final alive with a 16-run victory over South East Stars.
Opener Emma Lamb made 63 off 38 balls and Fi Morris scored 44 in Thunder’s 165-5.
Captain Bryony Smith (51) and Paige Scholfield (31) got Stars off to an excellent start with an opening stand of 87 but they both fell to Olivia Bell in the space of three balls.
Stars then collapsed to 127-8 and were eventually all out for 149 in the final over.
Western Storm eased to a seven-wicket victory over Central Sparks, but are unlikely to qualify for Finals Day unless results go their way in the last round.
Erin Burns made a fine 66 but Central Sparks could only reach 135-6 in their 20 overs.
Orla Prendergast steered the chase with an unbeaten 46 as Storm won with four balls to spare.