Dominating performances from Australia's women cricket stars in the Hundred just keep snowballing with Grace Harris, Charli Knott and Bath Mooney the latest to deliver brilliant match-winning hands in the English white-ball showpiece.

Harris, who pummelled the biggest innings of the competition on its opening day on Tuesday, ended the tournament's first week with masterly death bowling to enable London Spirit to edge Welsh Fire by just two runs in Cardiff.

Harris's young teammate Knott also came to the party in the Spirit's win, the 22-year-old allrounder earning the player-of-the-match honours with her 47 off 33 balls as well as a crucial wicket.

Their heroics came soon after another thriller in London on Saturday in which Mooney played the perfect captain's knock, a superb 70 off 45 balls, to earn Manchester Originals a two-run win over their Oval Invincibles hosts, who almost chased down the total with a half-century from Meg Lanning.

Pride of place, though, once again went to irrepressible allrounder Harris, who started off her latest big day by hitting the only six of the match in her cameo of 18 in the Spirit's 124 all out.

Then, in the field, she took a fine catch on the boundary off Knott's spin to get rid of the dangerous Tammy Beaumont as the Fire, who were being guided strongly by a fine knock from another Australian Jess Jonassen, appeared to be coasting to victory.

With just one five-ball 'over' remaining, Harris was called on to save the day for the Spirit with her crafty spinning, but it looked a hopeless cause with the visitors only three wickets down and needing just seven to win.

But Harris, who'd taken a final-over hat-trick to win a Women's Premier League match for UP Warriorz back in February, again proved nerveless.

She went for just four runs off five balls, having one catch off her bowling dropped before taking a wicket with her final delivery as Georgia Elwiss tried to hit the winning boundary only to be caught expertly by Charlie Dean, running back from mid-on.

Two balls earlier, Jonassen's hopes of guiding the visitors home had been ended by a brilliant piece of fielding from fellow Australian, wicketkeeper Georgia Redmayne, who, with gloves on, flicked the ball back skilfully on to the stumps to run her out.

Earlier, at the Oval, Mooney was thrilled to get the better of her old national captain and friend Lanning in their terrific batting duel.

Mooney gleaned more than half her side's total of 6-139 as she cracked 10 boundaries but Lanning, having guided the Invincibles to within 13 of victory in the chase with her second half-century of the week, miscued and was caught for 56 off 42 balls.

With Marizanne Kapp (19no) not quite able to get the Invincibles across the line, it only meant more frustration for Lanning, who'd scored 85 in another losing cause in their first match on Tuesday.

Mooney could only smile with relief. "'I've seen Meg win a lot of games chasing totals like that, so there's always a bit of fear in you when she's hitting the ball like that. She's been an amazing player for years.

"As a fan of the game, it's really nice to see here out there with a smile on her face and hitting the ball like she is, but glad we got her out in the end."