Loughborough Lightning 125 for 1 (Haynes 66*) beat Western Storm 124 for 6 (Gordon 3-19)
Loughborough Lightning established themselves as firm favourites for the 2018 Women's Kia Super League with a crushing victory over defending champions Western Storm at Edgbaston.
Chasing 125 to win, Lightning eased home with seven and a half overs to spare, a humbling margin for Storm, who had beaten Lightning at Taunton in a rain-reduced five-over thrash earlier in the campaign but this time were no match for their impressive opponents.
Australian opener Rachael Haynes led the way with her third half-century of the tournament, finishing on 66 not out from 40 deliveries including 10 fours and a six.
New Zealand allrounder Sophie Devine weighed in with 38 off 30 balls and picked up two wickets as Lightning displaced Storm at the top of the KSL table with one match remaining, the bonus point giving them a three-point lead into their final fixture, away to Yorkshire Diamonds on Saturday evening.
Storm take on Surrey Stars at The Oval. The team that finishes top of the table goes straight into the KSL Final at Hove on Monday week, which is preceded by a semi-final between second and third in the chart.
Lightning's tightly disciplined bowling attack had vindicated skipper Georgia Elwiss's decision to bowl first by restricting Storm to 124 for 6 in their 20 overs, the defending champions' lowest score in the tournament.
Spinner Kirstie Gordon had been the star of the show, dismissing all three of Storm's most potent batters, including the top scorer in the competition, Smriti Mandhana, who came into this match with an average of 77.40 and a strike rate but this time fell for 29.
An eventful Powerplay saw Mandhana riding her luck from the start on a day when she could never quite muster the destructive powers that had brought her the tournament's only hundred so far.
Unable to play with her usual freedom, the KSL's most prolific scorer escaped a stumping chance before she had got off the mark in Jenny Gunn's opening over, although the replay showed Lightning's appeal to be a little optimistic. That was followed by a genuine let-off in the sixth over when, on 17 and beginning to find her timing, she was put down at extra cover, where a stretching Elwiss had a good hand on the ball but could not hold on.
It looked like it might be a costly miss when Mandhana repeated the shot a couple of balls later, hitting seamer Devine over the head of the Lightning captain for her third boundary as Storm reached the end of the Powerplay at 43 for 1. They had lost opener Rachel Priest when the New Zealand batter sliced Devine to short third man, but there was plenty of batting to come.
England and Storm captain Heather Knight punished Sarah Glenn's legspin with a couple of boundaries but then a brilliant over from the left-arm spinner Gordon, one of the break-out players of the tournament, changed the complexion of the innings.
Called into the attack in the ninth over with Storm 60 for 1, Gordon claimed the major scalps of Mandhana and Knight with consecutive balls, the former failing as she tried to clear Elyse Villani on the long-off boundary. Gordon then came up with a beauty that turned past the outside edge to clip Knight's off stump.
Thereafter, Storm were never able to regain any consistent momentum as Gordon and fellow left-armer Linsey Smith combined with Elwiss's medium pace to produce a near-perfect bowling performance on a slow surface, seldom giving away any easy runs.
Gordon picked up a third success - her 14th of the tournament - and a third of Storm's batting trump cards when Stefanie Taylor hit her into the safe hands of Georgia Adams on the long-off boundary, giving her figures of 3 for 19 as the leading spin bowler in the competition.
Elwiss got in on the act with a deserved wicket when Villani grabbed a second catch in the deep, before doing well to hold on to a low chance at wide extra cover as Naomi Dattani became Devine's second victim in the final over of the innings.