Birmingham Phoenix 147 for 4 (E Jones 64) beat Northern Superchargers 133 for 6 (Winfield-Hill 64, Wolvaardt 32) by six wickets
Eve Jones hit a superb 64 and the Birmingham Phoenix later held their nerve defending 148 to claim the honours in their winner-takes-all women's Hundred clash with Northern Superchargers, putting on the cusp of qualification for the knockout stages.
Jones, the left-handed opener, underpinned Phoenix's 147 for 4 before Superchargers captain Lauren Winfield-Hill matched her score to put the hosts on course at 97 for 1 after 60 balls on a flat Emerald Headingley pitch.
But the third-placed Superchargers collapsed, slipping to 133 for 6 to lose for the fourth game running and allow the buoyant Phoenix to leapfrog them from fifth in the table with a third straight win.
They will now face Oval Invincibles at The Oval in Friday's effective semi-final following this 14-run win, barring a crushing win for London Spirit on Wednesday night against Welsh Fire.
Following seven boundaries in the contest's first 10 balls, five of them for captain Amy Jones, Phoenix's other Jones built on the early momentum and faced 47 balls.
Amy hit six fours in her 24 before slapping a full toss from the left-arm spin of Linsey Smith to mid-on to leave 33 for 2 after 15, while Eve hit the first of her three sixes down the ground off Central Sparks team-mate Liz Russell as the score reached 74 for 2 after 50.
Superchargers improved during the second 50 balls, with spinners Smith and Katie Levick sharing three wickets. Jones reached her second Hundred fifty off 39 balls shortly before falling off the 95th ball, caught at long-off, off Levick's legspin.
Winfield-Hill continued the flurry of boundaries at the start of the Superchargers chase, hitting six of her first 12 balls for four.
By the time Phoenix broke through as the offspin of Erin Burns had Jemimah Rodrigues caught at deep midwicket sweeping, Winfield-Hill had scored 29 of Superchargers' 30 runs.
The England star found an ally in South African Laura Wolvaardt, who also settled quickly in a 67-run partnership.
Winfield-Hill reached her fifty off 29 balls shortly before the halfway mark in the innings, where Superchargers reached at 79 for 1 with 69 more required, but Issy Wong had Winfield-Hill brilliantly caught at short third by Eve Jones to spark the revival.
Legspinner Abtaha Maqsood had Wolvaardt caught for 32 before Emily Arlott yorked the big hitting Australian Laura Kimmince and Kirstie Gordon got Alice Davidson-Richards stumped to leave Superchargers 119 for 5 after 89. Wong struck again as she comfortably defended 22 off the last five balls, finishing with 2 for 24.