Central Sparks were knocked off top spot to third in the Rachael Heyhoe Flint Trophy as they suffered their first defeat on a day when Southern Vipers and Northern Diamonds both won.
Skipper Georgia Adams led by example with 77 as Vipers beat Western Storm by eight wickets, earning the extra bonus point that takes them to the summit.
Diamonds beat South East Stars in a game of more than 500 runs in Leeds.
But Sparks lost to Thunder, while Lightning beat backmarkers Sunrisers.
Beaten for the first time since 2019 by Sparks in their last outing, Vipers responded in the manner of defending champions.
Adams was well backed by Maia Bouchier (57 not out) at Taunton as they reached 178-2 to win with 15.1 overs to spare.
“This is the perfect response after what was a pretty hard time last week,” said Adams. “We would have been happy with chasing anything around 250. We thought 280 was probably a par score, so were delighted to be set 178.”
Storm, weakened by the absence of England pair Heather Knight and Anya Shrubsole, have now lost three matches in succession.
Charlie Dean (3-27) and Lauren Bell (3-40) had earlier done the main damage to bowl out the hosts for 177.
Sparks stunned despite Eve’s excellence
The first defeat suffered by Central Sparks after opening up with three straight wins came despite an unbeaten 100 from captain Eve Jones at New Road.
She helped her side recover from 17-3, carrying her bat as her side were eventually bowled out for 203, spinner Hannah Jones (3-33) and Laura Jackson (3-35) impressing with the ball for the visitors.
Thunder openers Emma Lamb and Georgie Boyce put on 73 before England’s Sarah Glenn and fellow spinner Georgia Davis triggered a collapse to 97-5.
But Jackson hit 30 as the lower order rallied to secure Thunder’s second win of the campaign with just two wickets in hand and two overs to spare.
“It is very mixed feelings for me,” said Sparks skipper Jones. “I’d swap the hundred for a win any day.
“We were probably just 20-30 runs short with the bat and a couple of things didn’t quite go our way, a few mis-fields. But we still felt we were in with a shout to the last ball.”
The heartening return to professional cricket of former England wicketkeeper-batter Sarah Taylor was overshadowed by her team’s fantastic overall performance as Diamonds beat South East Stars by three wickets.
Kirstie White hit 73 off 90 balls as Stars reached 250-6 – and Diamonds looked in trouble when Taylor was out for two from five balls, the last of four wickets for 12 runs, as they slipped from 58-1 to 70-5.
But Jenny Gunn (50) and Beth Langston (59*) shared a stand of 90, following the lead of Dutch international Sterre Kalis’ earlier 76.
Langston hit the winning runs to secure a second win in four games with only four balls to spare.
Taylor, 32, retired from international cricket in 2019, citing anxiety issues, did not play at all in 2020 and had previously made just four T20 appearances for Sussex in May.
“I felt rusty,” she said. “But it was nice to dust the cobwebs off the legs, the back and the hands. For a first proper game of cricket, keeping wise, after a two-year break, I’m pretty happy with that.”
Bottom side Sunrisers slumped to their fourth defeat in four matches at Loughborough University’s Haslegrave Ground as Michaela Kirk’s half-century and four wickets for seamer Teresa Graves helped Lightning to a second win.
Naomi Dattani (65) and Kelly Castle (52) helped Sunrisers reach 206-9 after opting to bat first, but Lightning won with almost 10 overs to spare.
South African-born batter Kirk hit nine fours in her 57 off 66 balls, sharing good stands with both Bryce sisters, 57 with Sarah and 47 with Kathryn, before Abbey Freeborn hit seven fours in her 44 off 48 balls.
The Trophy resumes on 10 September with the first of three final rounds of group-stage fixtures, before the top two teams meet in the final on Saturday, 25 September.