South East Stars 275 for 8 (Davidson-Richards 79, Jones 47) beat Northern Diamonds 119 (Stonehouse 4-27, Moore 3-10) by 156 balls
New-ball seamer Alexa Stonehouse returned a career-best four for 27 to help South East Stars clinch a home semi-final in the Rachael Heyhoe Flint Trophy as they crushed already confirmed group stage winners Northern Diamonds by 156 runs at Durham.
A season's best run-a-ball 79 from Alice Davidson-Richards anchored the Stars' imposing 275 for eight in a final round group clash between first and second in the table at the Seat Unique Riverside before left-armer Stonehouse's opening seven-over burst was key in bowling the Diamonds out for 119 inside 37 overs.
The Diamonds disappointed in what was essentially a dead-rubber fixture for them. They failed to match the intensity of the Stars, for whom all-rounder Emma Jones also impressed with a career best 47.
Both regions, who finished with nine wins from 14 games, will find out next Saturday's semi-final opponents later today.
Having elected to bowl following a half-hour delay because of morning mist, the Diamonds failed to utilise helpful conditions despite an encouraging start.
Left-arm seamer Rachel Slater struck with the new ball when she had Stonehouse caught at mid-on before Abi Glen's seam accounted for the other opener, Chloe Hill, for 25 as the score fell to 53 for two in the 12th over.
The Hill wicket owed much to a sharp midwicket catch by Australian Erin Burns, who also claimed two wickets caught and bowled with her off-spinners.
From there, the Stars asserted their authority in overcast conditions.
Phoebe Franklin scorched a couple of cover driven boundaries off seam and hoisted Katie Levick for six over long-off in a useful 32 before being bowled by Phoebe Turner, who also trapped captain Kira Chathli lbw - 123 for four in the 24th.
A 50-stand between Aylish Cranstone and Davidson-Richards gave the Stars a platform heading into the final 20 overs, and the visitors were helped by a combination of sloppy ground fielding and some loose bowling.
Burns caught well, though, and took a skied return catch to remove Cranstone for 28.
Davidson-Richards, a former Yorkshire Diamond, hit nicely in the V en-route to a 56-ball fifty and became increasingly adventurous.
Towards the end of her 64-stand with sixth-wicket partner Jones, she pulled Beth Langston over deep midwicket for six but skied the same bowler to mid-on next ball - 237 for six in the 44th.
Jones drove well before falling just short of a maiden senior fifty, drilling another return catch to Burns in the penultimate over.
Then came the game's defining period as Diamonds slipped to an unrepairable 30 for five inside seven overs of their chase, played out in bright sunshine.
That collapse was sparked by Tilly Corteen-Coleman taking the new ball with her left-arm spinners and getting linchpin opener Lauren Winfield-Hill caught at short midwicket for two.
Rebecca Duckworth was then lbw to 19-year-old Stonehouse, who had opener Emma Marlow caught at square-leg and Langston lbw. The latter two came in the space of three balls in the 10th over.
Franklin's seam bowled Sterre Kalis in between.
Stars could now start planning for a home semi-final, while the Diamonds were contemplating a fourth defeat in 14 games.
Stonehouse had Burns caught behind added to two wickets in an over for off-spinner Kalea Moore.
Unbeaten Turner resisted for a career best 49 as Stonehouse returned to complete her 10-over allocation. But spinners Dani Gregory and Moore - three for 10 from 6.1 overs - wrapped up the Stars' victory.
