Yorkshire Diamonds 148 for 6 (Mooney 76) beat Loughborough Lightning 145 for 6 (Haynes 47) by three runs
Yorkshire Diamonds secured a notable consolation win against Kia Super League table-toppers Loughborough Lightning at Headingley.
The Diamonds fought superbly with the ball and in the field to defend a target of 149 and secure their third win.
The Lightning have still qualified directly for the final at Hove a week on Monday, where they will play the winner of the semi-final between Surrey Stars and champions Western Storm.
Left-arm spinner Thompson, in her first game of the campaign, was the pick of the bowlers with 2 for 18 from her four overs as the Lightning failed to get 14 off the last and finished on 145 for 6, losing by three runs.
Australian opener Beth Mooney underpinned the Diamonds' 148 for 6 with 76 off 50 balls, while left-arm spinners Linsey Smith and Kirstie Gordon claimed two wickets apiece.
The much-changed Diamonds, who handed first KSL appearances of 2018 to Sophie Munro and Thompson, posted a competitive total, centred around Mooney's second half-century.
But only youngster Bess Heath was able to provide notable support with 24. They shared 65 inside 10 overs for the second wicket to advance from 19 for 1 in the third when Smith bowled home captain Lauren Winfield.
Smith also uprooted the middle stump of Yorkshire's second Australian, Delissa Kimmince, who later bowled the last over of the match against Georgia Adams and Lucy Higham.
Gordon had Thea Brookes stumped for one and later Mooney caught low down at cover by Haynes.
Yorkshire were well placed at 108 for 3 after 15 overs and would have wanted more than 40 off the last five. In the end, it was enough.
Lightning skipper Sophie Devine swept Thompson's left-arm spin for six at the end of the first over of the chase and hit Beth Langston twice over the ropes in the fourth as the score moved to 30 without loss.
The second six, pulled out to deep backward square-leg was dropped over the rope by Alice Monaghan. However, two balls later, in the next over, Devine was caught at deep mid-wicket off Brookes' offspin.
Rachel Haynes took on the lead role with 47 before falling as the game tightened up at 95 for 3 in the 13th over. She hoisted the seam of Davidson-Richards to deep mid-wicket, where Monaghan atoned for her earlier error.
Haynes had shared 52 for the second wicket with Amy Jones, who fell when she chipped Thompson to cover as the score fell to 83 for 2 at the start of the eleventh.
The Diamonds were without talismanic England all-ounder Katherine Brunt having opted to rest her. But they were able to build pressure in the second half of the chase, taking the target to 38 off five with Loughborough three wickets down.
Thompson had Elyse Villani stumped at the start of the 17th before Brookes had Georgia Elwiss caught at deep mid-wicket in the 18th as the target became 19 off two overs and 14 off the last.