Mooney is showing her class - her international pedigree.
Spirit 35-0
Spirit are flying!
Consecutive boundaries to Beth Mooney off Lauren Bell, one crunched through the off-side and one tickled away past the wicketkeeper.
Missed stumping
Spirit 27-0
Oh! Freya Kemp almost has her wicket, as Grace Scrivens steps out of her crease, but wicketkeeper Carla Rudd drops the ball! A bit of a sloppy mistake and Scrivens gets a life.
Aaaand Kemp's next ball bounces sharply over Rudd's shoulder and runs away for four! Bit messy from the Brave that over, and they've gifted some runs to the Spirit.
Spirit 23-0
First six of the day!
Beth Mooney clips Freya Kemp's second ball into the stands - pure class.
Kemp's first ball was a wide, so this will be a test for the young quick bowler.
Post update
Carlos Brathwaite
West Indies all-rounder on BBC Radio
There has been a concerted effort bowl very straight. It has worked so far.
Spirit 14-0
Bit of pressure building on young Grace Scrivens, who tries to smash Shrubsole through the off-side but completely misses.
Beth Mooney comes down for a chat with the 18-year-old, as just one run comes from Shrubsole's first five.
18 years old. That's criminal.
Spirit 13-0
Cheers echo around the ground as Anya Shrubsole is into the attack for the first time, the former England bowler and Brave's captain.
Spirit 13-0
Four more to Beth Mooney, smashing her fellow Australian Molly Strano to the ropes.
I'd imagine the Aussies will be coping a bit better with the temperatures today.
Post update
Henry Moeran
BBC Radio
Grace Scrivens is a lesser-spotted England left-hander...
Spirit 6-0
A classy piece of fielding from Sophia Dunkley saves an almost certain boundary from the bat of Grace Scrivens, who has to settle for a single.
The t-shirt tans are going to be strong after today.
Spirit 4-0
A lovely start!
Beth Mooney clips the ball effortlessly off her legs for four runs! Maia Bouchier chases the ball all the way, puts in a decent effort to dive and stop it but instead belly flops unsuccessfully over the rope.
Post update
Just looking at Brave's batting and yeah, good luck to all the bowlers.
But we've got to wait a bit to see them, as they're in the field. Australian great Beth Mooney and youngster Grace Scrivens are opening the batting, with Lauren Bell taking the first ball.
Here we go...
Post update
Melissa Story
BBC Test Match Special
The Brave probably have the best batting line-up in this competition.
Today's match-up: An Aussie star and an English starlet
Getty Images/BBC SportCopyright: Getty Images/BBC Sport
Two of cricket's best and in-form female batters will be going head-to-head this afternoon.
Sophia Dunkley is one of England's rising star who seems destined for the very top.
The 24-year-old made her England debut at the World T20 in 2018 and has gone on to become a key member of the middle order, finishing as England's second highest run-scorer at the World Cup earlier this year.
Dunkley was the most prolific Englishwoman in last year's Hundred and only two players scored more than her 244 runs.
She comes into this year's tournament in fine form having scored 180 runs across three one-day internationals against South Africa earlier this summer, including hitting her maiden white-ball century in the second ODI at Bristol. Dunkley also hit her maiden T20 half-century to help England wrap up a multi-series win against the Proteas.
Beth Mooney meanwhile arrives at the Hundred fresh from playing a key role in Australia's Commonwealth Games success, with her 61 from just 41 balls helping Meg Lanning's side to a nine-wicket win over India in the final.
The 28-year-old was named the leading women's cricketer in the world in 2020 and was the leading run-scorer for Perth Scorchers on their way to the title in the 2021-22 Women's Big Bash.
Mooney also proved she was made from tough stuff earlier this year when she carried on playing in the Ashes despite having her jaw wired shut.
Post update
Henry Moeran
BBC Radio
It is seriously warm out there.
The teams
London Spirit: Grace Scrivens, Beth Mooney (wk), Amelia Kerr, Danielle Gibson, Sophie Luff, Naomi Dattani, Alice Monaghan, Charlie Dean (c), Amara Carr, Freya Davies, Megan Schutt.
Charlie Dean, London Spirit's new, young captain in place of Heather Knight, opts to bat first on a scorching day at Southampton.
Anya Shrubsole is leading the opposition, and says she would've bowled first anyway. Everyone's a winner.
Post update
Oval Invincibles started their title defence in fine style last night, sweeping aside the Northern Superchargers pretty easily.
Welcome
Hello! Bit hot, isn't it?
Whether you're sunbathing (brave), at the beach (jealous) or hiding inside from the heat (sensible), stay with us for all the action of Southern Brave and London Spirit - with the women kicking things off.
Last year's finalists Brave are looking strong again, with Danni Wyatt and Smriti Mandhana firing at the top of the order, but Spirit have recruited well and have some strong overseas players.
Live Reporting
Matthew Henry and Ffion Wynne
All times stated are UK
Post update
Carlos Brathwaite
West Indies all-rounder on BBC radio
Mooney is showing her class - her international pedigree.
Spirit 35-0
Spirit are flying!
Consecutive boundaries to Beth Mooney off Lauren Bell, one crunched through the off-side and one tickled away past the wicketkeeper.
Missed stumping
Spirit 27-0
Oh! Freya Kemp almost has her wicket, as Grace Scrivens steps out of her crease, but wicketkeeper Carla Rudd drops the ball! A bit of a sloppy mistake and Scrivens gets a life.
Aaaand Kemp's next ball bounces sharply over Rudd's shoulder and runs away for four! Bit messy from the Brave that over, and they've gifted some runs to the Spirit.
Spirit 23-0
First six of the day!
Beth Mooney clips Freya Kemp's second ball into the stands - pure class.
Kemp's first ball was a wide, so this will be a test for the young quick bowler.
Post update
Carlos Brathwaite
West Indies all-rounder on BBC Radio
There has been a concerted effort bowl very straight. It has worked so far.
Spirit 14-0
Bit of pressure building on young Grace Scrivens, who tries to smash Shrubsole through the off-side but completely misses.
Beth Mooney comes down for a chat with the 18-year-old, as just one run comes from Shrubsole's first five.
18 years old. That's criminal.
Spirit 13-0
Cheers echo around the ground as Anya Shrubsole is into the attack for the first time, the former England bowler and Brave's captain.
Spirit 13-0
Four more to Beth Mooney, smashing her fellow Australian Molly Strano to the ropes.
I'd imagine the Aussies will be coping a bit better with the temperatures today.
Post update
Henry Moeran
BBC Radio
Grace Scrivens is a lesser-spotted England left-hander...
Spirit 6-0
A classy piece of fielding from Sophia Dunkley saves an almost certain boundary from the bat of Grace Scrivens, who has to settle for a single.
The t-shirt tans are going to be strong after today.
Spirit 4-0
A lovely start!
Beth Mooney clips the ball effortlessly off her legs for four runs! Maia Bouchier chases the ball all the way, puts in a decent effort to dive and stop it but instead belly flops unsuccessfully over the rope.
Post update
Just looking at Brave's batting and yeah, good luck to all the bowlers.
But we've got to wait a bit to see them, as they're in the field. Australian great Beth Mooney and youngster Grace Scrivens are opening the batting, with Lauren Bell taking the first ball.
Here we go...
Post update
Melissa Story
BBC Test Match Special
The Brave probably have the best batting line-up in this competition.
Today's match-up: An Aussie star and an English starlet
Two of cricket's best and in-form female batters will be going head-to-head this afternoon.
Sophia Dunkley is one of England's rising star who seems destined for the very top.
The 24-year-old made her England debut at the World T20 in 2018 and has gone on to become a key member of the middle order, finishing as England's second highest run-scorer at the World Cup earlier this year.
Dunkley was the most prolific Englishwoman in last year's Hundred and only two players scored more than her 244 runs.
She comes into this year's tournament in fine form having scored 180 runs across three one-day internationals against South Africa earlier this summer, including hitting her maiden white-ball century in the second ODI at Bristol. Dunkley also hit her maiden T20 half-century to help England wrap up a multi-series win against the Proteas.
Beth Mooney meanwhile arrives at the Hundred fresh from playing a key role in Australia's Commonwealth Games success, with her 61 from just 41 balls helping Meg Lanning's side to a nine-wicket win over India in the final.
The 28-year-old was named the leading women's cricketer in the world in 2020 and was the leading run-scorer for Perth Scorchers on their way to the title in the 2021-22 Women's Big Bash.
Mooney also proved she was made from tough stuff earlier this year when she carried on playing in the Ashes despite having her jaw wired shut.
Post update
Henry Moeran
BBC Radio
It is seriously warm out there.
The teams
London Spirit: Grace Scrivens, Beth Mooney (wk), Amelia Kerr, Danielle Gibson, Sophie Luff, Naomi Dattani, Alice Monaghan, Charlie Dean (c), Amara Carr, Freya Davies, Megan Schutt.
Southern Brave: Danni Wyatt, Smriti Mandhana, Sophia Dunkley, Maia Bouchier, Georgia Adams, Freya Kemp, Molly Strano, Amanda-Jade Wellington, Anya Shrubsole (c), Carla Rudd (wk), Lauren Bell.
London Spirit win the toss and bat first
Charlie Dean, London Spirit's new, young captain in place of Heather Knight, opts to bat first on a scorching day at Southampton.
Anya Shrubsole is leading the opposition, and says she would've bowled first anyway. Everyone's a winner.
Post update
Oval Invincibles started their title defence in fine style last night, sweeping aside the Northern Superchargers pretty easily.
Welcome
Hello! Bit hot, isn't it?
Whether you're sunbathing (brave), at the beach (jealous) or hiding inside from the heat (sensible), stay with us for all the action of Southern Brave and London Spirit - with the women kicking things off.
Last year's finalists Brave are looking strong again, with Danni Wyatt and Smriti Mandhana firing at the top of the order, but Spirit have recruited well and have some strong overseas players.
We'll bring you the toss and team news soon!