ALEX MacDonald registered career-best figures to put the skids under Western Storm and help Northern Diamonds achieve a dramatic one-wicket win in the Charlotte Edwards Cup.

Diamonds skipper Holly Armitage won the toss at the Cooper Associates County Ground, Taunton, and opted to field, a decision which reaped dividends when MacDonald took 4-17.

Undermined by poor shot selection and unable to build meaningful partnerships, Storm posted a below-par 106-9, with Katie George making 21 and Nat Wraith 20.

But the hosts came roaring back into contention as Danielle Gibson, Alex Griffiths and Nicole Harvey claimed two wickets apiece, and Diamonds lurched to 96-9.

It required all of Jenny Gunn's vast experience to see the visitors over the line, the former England international hitting the winning four off the final ball to finish unbeaten on 27 from 21 balls.

Put into bat, Storm were up against it from the outset, Linsey Smith pinning Georgia Hennessy lbw without scoring in the first over, and then holding a catch at point as Gibson succumbed to Gunn.

When Phoebe Graham located Sophie Luff's outside edge and Sarah Taylor took a brilliant diving catch at the second attempt behind the stumps, Storm had lost their captain for a duck and were under duress at 28-3 in the fourth over.

Dropped on 11 by Katie Levick off the bowling of Graham in the sixth over, George made good her escape to accrue 21 valuable runs from 23 balls, striking a brace of fours in the process.

Chancing her arm once too often though, she then hoisted a delivery from MacDonald high to Ami Campbell at deep mid-on and exited at a crucial juncture in the innings, with the score on 64-5 at the halfway stage.

Former Gloucestershire bowler MacDonald struck again in her next over, accounting for Griffiths and then Lauren Parfitt, as Storm subsided further to 76-7 in the 13th over.

Wraith mustered tail-end defiance, contributing a forthright 20 from 21 balls, before Smith returned to remove her off stump and complete a handy return of 2-15.

Emily Edgecombe struck an early blow for Storm, having Hollie Armitage (5) caught by Wraith in the first over, but Leah Dobson and Campbell staged a progressive alliance of 27 in three overs to lay solid foundations.

Yet Storm stuck to their task in the field, and when Griffiths (2-28) removed Dobson and Campbell in the space of five balls in the fifth over, and Gibson then bowled MacDonald (6), there was the merest hint of an unexpected outcome.

The fightback was well and truly on when Griffiths performed a brilliant stop and throw from the deep square leg boundary to run out Taylor (11), the former England star falling inches short in pursuit of a second run.

Dutch international Sterre Kalis (14) played down the wrong line and was clean bowled by the impressive Gibson (2-9), at which point Diamonds were teetering on 78-7 and heavily reliant upon veteran campaigner Gunn.

Off-spinner Harvey (2-17) accounted for Smith and Graham in the penultimate over to set-up a tense finale.

But with 10 needed from the final over, Gunn held her nerve, lofting a length ball from Griffiths over mid-on to clinch a memorable victory at the death.

Reacting to the defeat, Storm captain Sophie Luff said: "It was probably a great game to watch for the neutral, but a difficult one to be on the wrong end of.

"I cannot fault the players for the way they battled back in the field and we could easily have won it.

"We put the ball in the right areas more often than not, and Danielle Gibson and Alex Grifiths bowled really well.

"But we always knew Jenny Gunn was still to come and her experience has helped get Diamonds over the line in the end.

"It's frustrating, because our batting is not firing at the moment and the senior players, myself included, have to take responsibility for that.

"We're not building partnerships, players are getting in and then giving their wickets away, and 106-9 was never going to be enough on that pitch."

With The Hundred running between July 21 and August 21, Storm's next fixture is not until Wednesday, August 25, at home to Thunder.