Birmingham Phoenix were eventually bowled out for 99 as their difficult campaign ended with a whimper.
Both teams were hampered by the weather at the start of the Hundred.
But Amelia Kerr finished with 4-13 to make sure London Spirit could finish with a smile.
Post update
London Spirit captain Charlie Dean on Sky Sports: "Massively important for us to finish on a high. We've spoken a lot about how we want to play so it was very special to put in a complete performance finally.
"Grace Harris and Dani Gibson is a great combination at the top. They haven't fired at their very best for us but it was great to see them go out and give us that platform today and allow us to post such a big total.
"I might retire as captain now, that's good for my record!
But it's something I'm grateful to get experience in doing and it's a part of my game that I definitely want to develop.
"We've been very clear with our plans throughout the tournament but we had a bit of a free pass today. It's a shame we left it late to put it all together but hopefully we can take it in to next year."
Post update
Harris' 87 from 47 balls is the reason why she is named the Match Hero.
A very entertaining performance.
Post update
Match Hero, London Spirit's Grace Harris on Sky Sports: "It's definitely one of my better days in England. I'm very happy to contribute.
"I loved that pitch as a batter. It was great to bat on.
"We wanted to finish on a positive and play freely. Personally, I have battled with that mentality so I was very pleased to go out and bat in my own style. I can overthink sometimes, especially when I've been moving around in the order.
"Both personally and as a team, it's nice to finish on a high.
"Heather Knight is a fantastic captain and it's been great to play under her and to learn from her. I have had a ball in this competition. It would have been nice to contribute a bit more but hopefully I can come back next year, we'll see!"
Post update
That concludes the group stages of the women's competition.
Southern Brave are through to the final, and will be joined by one of Northern Superchargers or Welsh Fire.
Birmingham Phoenix finish bottom of the table without a single victory, while that big win sees London Spirit leapfrog Manchester Originals into sixth.
London Spirit won by 73 runs
London Spirit finish their campaign with a complete thrashing of Birmingham Phoenix!
Very little that the last pair could do with such a big target to chase so Katie Levick has a swing, misses, and is bowled.
Amelia Kerr finishes with a fabulous 4-13.
Phoenix 99-9
It's been a dominant performance from Spirit with both bat and ball.
Charis Pavely and Katie Levick are the last pair for Phoenix.
WICKET
Arlott c Harris b Glenn 5 (Phoenix 99-9)
It's almost over.
Smacked down the ground, caught on the boundary.
And repeat.
WICKET
Wong c Kerr b Gibson 1 (Phoenix 97-8)
Another wicket, another brilliant Amelia Kerr catch.
Issy Wong becomes the latest Phoenix batter to try and whack a few, but is caught in the deep. A sprawling Kerr takes another smart grab and victory is in sight for London Spirit.
Phoenix 93-7
Emily Arlott leaves her first ball.
Phoenix need 80 runs from 35 balls.
WICKET
E Jones b Kerr 12 (Phoenix 92-7)
A beautiful bit of bowling from Amelia Kerr and the Phoenix skipper departs.
Eve Jones skips down the track, bit the ball turns through her defence and clips leg stump.
WICKET
Freeborn run out Gibson 11 (Phoenix 88-6)
Oh dear.
Abbey Freeborn comes back for a very optimistic second run after dabbing into the leg side but Dani Gibson is way too quick.
She picks up one-handed with a pinpoint throw to the keeper and Freeborn is way short.
Phoenix 83-5
Target 173
Cries of 'catch it!' follow another lofted drive from Eve Jones but it lands safely in front of the fielder at long-on.
Jones and Abbey Freeborn are trying valiantly to find the boundary but going absolutely nowhere.
Phoenix 78-5
Target 173
Halfway through the chase and London Spirit are firmly in control.
WICKET
Burns c Gibson b Kerr 13 (Spirit 69-5)
The wickets continue to tumble for Birmingham Phoenix.
Erin Burns tries to whack another one down the ground but a waiting Dani Gibson accepts the catch.
WICKET
A Jones c Dean b Kerr 14 (Phoenix 66-4)
Chipped tamely to mid-off and Spirit have their fourth.
Amy Jones just seemed to be struggling for rhythm, falling for a run-a-ball 14 as she tries to force the scoring along but can only softly loft the ball the a waiting Charlie Dean.
Phoenix 60-3
Target 173
Just five singles ticked off Kerr's first set, as injured Spirit captain Heather Knight watches on behind a pair of sunglasses from the dugout.
Post update
Here's how London Spirit took their first wicket, thanks to some excellent work from Amelia Kerr.
Phoenix 55-3
Target 173
Well, Erin Burns isn't going to hang around.
She smacks her first two balls for four straight down the ground.
Live Reporting
Ffion Wynne and Sam Drury
All times stated are UK
Latest PostPost update
Right, we'll take a quick break before the men's match starts and we will be live with you from 18:15 BST.
Here's Sam Drury's match report of the women's fixture for you to enjoy before then.
In a bit!
Post update
Birmingham Phoenix were eventually bowled out for 99 as their difficult campaign ended with a whimper.
Both teams were hampered by the weather at the start of the Hundred.
But Amelia Kerr finished with 4-13 to make sure London Spirit could finish with a smile.
Post update
London Spirit captain Charlie Dean on Sky Sports: "Massively important for us to finish on a high. We've spoken a lot about how we want to play so it was very special to put in a complete performance finally.
"Grace Harris and Dani Gibson is a great combination at the top. They haven't fired at their very best for us but it was great to see them go out and give us that platform today and allow us to post such a big total.
"I might retire as captain now, that's good for my record!
But it's something I'm grateful to get experience in doing and it's a part of my game that I definitely want to develop.
"We've been very clear with our plans throughout the tournament but we had a bit of a free pass today. It's a shame we left it late to put it all together but hopefully we can take it in to next year."
Post update
Harris' 87 from 47 balls is the reason why she is named the Match Hero.
A very entertaining performance.
Post update
Match Hero, London Spirit's Grace Harris on Sky Sports: "It's definitely one of my better days in England. I'm very happy to contribute.
"I loved that pitch as a batter. It was great to bat on.
"We wanted to finish on a positive and play freely. Personally, I have battled with that mentality so I was very pleased to go out and bat in my own style. I can overthink sometimes, especially when I've been moving around in the order.
"Both personally and as a team, it's nice to finish on a high.
"Heather Knight is a fantastic captain and it's been great to play under her and to learn from her. I have had a ball in this competition. It would have been nice to contribute a bit more but hopefully I can come back next year, we'll see!"
Post update
That concludes the group stages of the women's competition.
Southern Brave are through to the final, and will be joined by one of Northern Superchargers or Welsh Fire.
Birmingham Phoenix finish bottom of the table without a single victory, while that big win sees London Spirit leapfrog Manchester Originals into sixth.
London Spirit won by 73 runs
London Spirit finish their campaign with a complete thrashing of Birmingham Phoenix!
Very little that the last pair could do with such a big target to chase so Katie Levick has a swing, misses, and is bowled.
Amelia Kerr finishes with a fabulous 4-13.
Phoenix 99-9
It's been a dominant performance from Spirit with both bat and ball.
Charis Pavely and Katie Levick are the last pair for Phoenix.
WICKET
Arlott c Harris b Glenn 5 (Phoenix 99-9)
It's almost over.
Smacked down the ground, caught on the boundary.
And repeat.
WICKET
Wong c Kerr b Gibson 1 (Phoenix 97-8)
Another wicket, another brilliant Amelia Kerr catch.
Issy Wong becomes the latest Phoenix batter to try and whack a few, but is caught in the deep. A sprawling Kerr takes another smart grab and victory is in sight for London Spirit.
Phoenix 93-7
Emily Arlott leaves her first ball.
Phoenix need 80 runs from 35 balls.
WICKET
E Jones b Kerr 12 (Phoenix 92-7)
A beautiful bit of bowling from Amelia Kerr and the Phoenix skipper departs.
Eve Jones skips down the track, bit the ball turns through her defence and clips leg stump.
WICKET
Freeborn run out Gibson 11 (Phoenix 88-6)
Oh dear.
Abbey Freeborn comes back for a very optimistic second run after dabbing into the leg side but Dani Gibson is way too quick.
She picks up one-handed with a pinpoint throw to the keeper and Freeborn is way short.
Phoenix 83-5
Target 173
Cries of 'catch it!' follow another lofted drive from Eve Jones but it lands safely in front of the fielder at long-on.
Jones and Abbey Freeborn are trying valiantly to find the boundary but going absolutely nowhere.
Phoenix 78-5
Target 173
Halfway through the chase and London Spirit are firmly in control.
WICKET
Burns c Gibson b Kerr 13 (Spirit 69-5)
The wickets continue to tumble for Birmingham Phoenix.
Erin Burns tries to whack another one down the ground but a waiting Dani Gibson accepts the catch.
WICKET
A Jones c Dean b Kerr 14 (Phoenix 66-4)
Chipped tamely to mid-off and Spirit have their fourth.
Amy Jones just seemed to be struggling for rhythm, falling for a run-a-ball 14 as she tries to force the scoring along but can only softly loft the ball the a waiting Charlie Dean.
Phoenix 60-3
Target 173
Just five singles ticked off Kerr's first set, as injured Spirit captain Heather Knight watches on behind a pair of sunglasses from the dugout.
Post update
Here's how London Spirit took their first wicket, thanks to some excellent work from Amelia Kerr.
Phoenix 55-3
Target 173
Well, Erin Burns isn't going to hang around.
She smacks her first two balls for four straight down the ground.