A destructive half-century from Danni Wyatt wasn't enough as Southern Vipers fell short by 15 runs in their Kia Super League clash against Western Storm.
Heather Knight and Fran Wilson scored half centuries and staged a magnificent stand of 115 for the third wicket as Kia Super League title favourites Western Storm defeated nearest rivals Southern at the Bristol County Ground.
Knight won the toss, elected to bat first and top-scored with 61 from 48 balls, while England team-mate Wilson contributed 50 not out as the hosts posted a formidable 170-3 in 20 overs.
Wyatt played an explosive innings of 56 and dominated a stand of 73 for the second wicket with fellow England batsman Tammy Beaumont to keep Vipers in the hunt. But consistent off spinner Claire Nicholas claimed the key wickets of Wyatt and overseas star Stafanie Taylor to turn the game in Storm's favour, while England seamers Anya Shrubsole and Freya Davies weighed in with figures of 3-39 and 4-18 respectively as Vipers came up short on 155-9.
Still unbeaten this season, Storm have now registered seven straight wins, lead second-placed Vipers by 10 points with three group games to play and are now guaranteed a place at Finals Day in Hove on Sunday, September 1.
Their latest victory was founded upon a superb partnership between the experienced Knight and Wilson, who came together at 54-2 in the seventh over and took the game away from the Vipers.
These two were afforded a solid platform by in-form openers Rachel Priest and Smriti Mandhana, both of whom posted 24 runs from 18 balls in a stand of 43. Priest was pinned lbw by Lauren Bell having accrued five boundaries and Mandhana fell to Amanda Wellington's leg breaks, held at long-on in the act of trying to clear the boundary.
If Vipers believed that double breakthrough would herald a spell of dominance, they were made to think again as Knight and Wilson combined deft placement and frenetic running between the wickets to keep the scoreboard moving.
Having advanced the score to 104-2 by the end of the 14th over, the third wicket pair launched a concerted assault which yielded 66 from the final six overs as Vipers, under sustained pressure, wilted in the field.
Knight was first to reach 50, attaining that landmark via 40 balls with 7 fours. The England captain then carved Bell high over mid-wicket to register the only six of the innings as she sought acceleration in the closing overs.
Of the bowlers, only off spinner Taylor emerged with credit, the former Storm all-rounder having Knight caught at long-on to finish with 1-20 from four overs.
Wilson was still there at the end, scampering a quick single off the final ball to raise an unbeaten 50 from 36 balls, an innings adorned with 7 fours.
Storm struck a crucial blow in the second over, England seamer Freya Davies inducing Suzie Bates to edge a catch behind for two.
Unperturbed by the loss of her skipper, England opener Wyatt took the game to Storm, adopting the aerial route to smash 8 fours and 2 sixes in a whirlwind innings of 56 from 32 balls. While she remained at large in a stand of 73 with Tammy Beaumont for the second wicket, Vipers were in with a chance.
Urgently requiring a breakthrough, Knight called Nicholas back into the attack to bowl the tenth over, with immediate results. The wily Welsh off spinner forced a mistake from Wyatt and Deepti Sharma, stationed at backward point, took a brilliant diving catch to dismiss the England opener and reduce the visitors to 76-2.
Taking the pace off the ball proved an effectove tatctic during the middle overs as spinners Knight, Nicholas and Sharma sought to restrict the run rate and build pressure from both ends.
Beaumont succumbed when, having raised 25 from 31 balls, she hoisted England team-mate Shrubsole to Sharma at long-on with the score on Nelson.
Heavily depndent upon the experienced Taylor, Vipers suffered a further blow when the West Indies international played across the line to Nicholas and was caught by Wilson on the mid-wicket boundary for a 24-ball 28 with the score on 120 in the 16th over.
The game was effectively up when Davies and Shrubsole combined to remove Maia Boucher, Marie Kelly, Paige Schofield and Wellington in quick succession as Vipers' reply lost crucial momentum at the death.