Unbeaten Western Storm reaffirmed their status as Kia Super League title favourites when beating defending champions Surrey Stars by four runs at the Cooper Associates County Ground.

Rachel Priest top-scored with 44 and Sophie Luff and Deepti Sharma contributed 32 apiece as Storm posted 159-8 after being put in to bat.

Sarah Taylor's brilliant innings of 73 from 54 balls set-up a tense finish, but Storm held their nerve, off spinner Sharma claiming 3-18 as Stars came up agonisingly short on 158-8.

Already guaranteed a place at Finals Day in Hove on September 1, Storm have now won all eight of their fixtures and, with two group games remaining, are attempting to become the first side in KSL history to go through a season unbeaten.

Storm's latest victory was achieved despite some of their most consistent performers failing to deliver. Not as prolific as in her first season, when she finished top-scorer in KSL, Smriti Mandhana edged a length ball from South African seamer Marizanne Kapp to slip and departed for a five-ball duck.

On this occasion, the fireworks were provided by fellow opener Priest, who blasted a quickfire 44 in 16 balls, all but two of her runs being plundered from Mady Villiers' off spin in the form of boundaries.

Having helped herself to 5 sixes and 3 fours, the 34-year-old New Zealander then surrendered her wicket in disappointing fashion, finding Kapp at long-on to afford the chastened Villiers much-needed respite.

Once again, her efforts provided a platform for the in-form third-wicket pairing of Fran Wilson and Heather Knight, who joined forces with the score on 48-2 at the end of the fifth over. But neither was able to impose themselves on this occasion, Knight beaten by the flight and bowled by van Niekerk for 13 and Wilson bowled by Laura Marsh for 27 as Storm faltered in the face of spin from both ends.

More accustomed to closing out an innings, Luff and Sharma found themselves charged with the task of rebuilding from 88-4 in the tenth over. Aided and abetted by clever placement and feverish running, their fifth-wicket alliance yielded 65 crucial runs in 8.4 overs as Storm recovered sufficiently to post a competitive total.

Positive in her running, Luff raised 32 from 28 balls, while Sharma required two deliveries fewer to post the same total. Both accrued 3 fours before surrendering to Nat Sciver, who claimed three wickets in five balls in the penultimate over to restrict the hosts.

Beaten in their last three outings, Stars' top-order batting woes continued, out-of-sorts openers van Niekerk and Liselle Lee falling to Sharma and Claire Nicholas respectively without scoring.

Taylor found a willing ally in Sciver and the third wicket pair added 70 in 9 overs to repair the early damage and threaten to make a game of it. Having raised 31 from 26 balls and hit 5 fours, Sciver fluffed her lines, hoisting Sharma to Wilson at deep mid-wicket in the 13th over.

Needing a further 74 runs from 45 balls to become the first side to inflict defeat on Storm in 2019, the visitors were heavily dependent upon Taylor, who went to 50 via 42 balls. But her quest to win the game single-handedly came unstuck when, seeking a 12th boundary, the England batsman top-edged a Freya Davies delivery to Nicholas at short fine leg.

Stars still required 31 runs from 19 balls and suffered a further setback when Sharma had Kapp caught at short fine leg for 23 in the 18th over. Bryony Smith was run out by Luff, leaving Marsh and Villiers to score 11 off the final over.

England seamer Anya Shrubsole then removed Villiers and Eva Gray, holding her nerve under intense pressure to secure a dramatic victory, Storm's eighth in as many KSL games played at Taunton.

Sophie Luff said: "We're really proud of our record. It's eight straight wins and we're looking to go through the group campaign unbeaten.

"There are two games left and we need to be ruthless, because that will stand us in good stead for the final.

"We've shown we can win games from all manner of positions and in all sorts of different scenarios and that has to fill you with confidence as a team.

"I think we have greater depth this year and more players have contributed match-winning performances.

"The fact we've got across the line in a few tight finishes before today certainly helped us out there.

"Sarah Taylor is a class player and her innings threatened to take it away from us.

"But nobody panicked, we stuck to our plans and held our nerve at the death. To defend 160 on that pitch in the way we did is a really good effort and we have to be pleased with it.

"I've spent a lot of time waiting to come in and bat this year and it was good to get to the middle a bit earlier for once.

"Deepti (Sharma) and I had to rebuild the innings and we knew we needed a good stand to get us back on track. It was just a pity that one of us couldn't stay until the end to get us up to 170."

Copy supplied by Andy Stockhausen, ECB Reporters' Network