After an opening day defeat to Central Sparks, it was important for the Diamonds to bounce back two days later - against Lightning at Kibworth on Bank Holiday Monday (May 31).
And they did it in style thanks to England greats past and present, Jenny Gunn and Katherine Brunt, who made 40 and claimed 4-23 respectively.
Like the Sparks game, this was a thriller. But swap runs galore for a low-scoring affair in leafy Leicestershire.
Having been inserted, the Diamonds slumped to 50-6 inside 15 overs, including three early wickets for medium pacer Kathryn Bryce.
However, a superb seventh-wicket stand of 81 between Gunn and fellow all-rounder Alex MacDonald (39) inside 24 overs ensured the visitors crucially posted 151 all out.
In reply, brilliant Brunt gave the Diamonds the perfect start by ousting Sarah Bryce and sister Kathryn inside three overs - 7-2.
And, when Nat Sciver trapped Tammy Beaumont lbw for two, Lightning were tottering at 57-5 inside 18 overs.
But they recovered stoutly, capped by a 39-run stand between Yvonne Graves and Kirstie Gordon for the ninth wicket, leaving the score at 139-8 with 15 balls remaining and 12 needed.
But enter Brunt, who had Graves caught at mid-on by Gunn to clinch her fourth wicket.
Like Graves, Gordon also made 19 and was still at the crease with 10th-wicket partner Sophie Munro and only seven needed off two overs.
Thankfully, Beth Langston sparked jubilation by getting Gordon caught behind, with the Diamonds up and running by a six-run margin.