Northern Diamonds 178 for 7 (Kalis 66*, Winfield-Hill 45) beat South East Stars 223 (Dunkley 101*, Woolston 5-37) by three wickets (DLS method)
Dutch international Kalis held her nerve amidst the loss of three quick wickets, with the Diamonds falling from 146 for 2 to 150 for 5. But later, with four needed off the last over from Bryony Smith, Lizzie Scott hit the winning runs with two balls remaining.
The champions have now won three and lost two of their opening five games. The Stars have the same record but are a point better on 15 ahead of the break for the start of the Charlotte Edwards Cup next week.
After Woolston took advantage of extra bounce from the Peasholm Park End, Dunkley was reserved before opening her shoulders late on. Dunkley hit three fours in a 60-ball fifty before reaching 100 off 100 balls, including another four fours and a pulled six.
After inviting the Stars to bat, Woolston had Aylish Cranstone - undone by extra bounce - caught by Leah Dobson running around to short mid-off following a leading edge, leaving the Stars at 9 for 1 in the third over.
Captain Smith and fellow England allrounder Alice Davidson-Richards both then fell in identical fashion off Woolston, pulling her out to Abi Glen at deep midwicket. The first catch was an excellent effort at head height following a particularly well-struck shot. Sandwiched in between, opener Kira Chathli edged the same bowler behind.
The Davidson-Richards wicket was the first of two wickets to fall in the 11th over, with in-form Paige Scholfield caught and bowled by Woolston off a leading edge.
It was 55 for 5, and the 20-year-old from Stockton-on-Tees was enjoying a memorable day in only her sixth senior appearance for the Diamonds.
Kalis then took a superb low catch at backward point to help seamer Abigail Glen dismiss Phoebe Franklin for a settling 26, ending a 45-run stand with Dunkley. And hope of a Stars recovery was now pretty much all in Dunkley's hands.
Wickets falling around her forced a more reserved approach. But, after Woolston's new-ball partner Scott struck twice to remove Tash Farrant and Ryana Macdonald-Gay, leaving the Stars at 154 for 8 in the 31st over, Dunkley decided to change her approach. She pulled Hollie Armitage's leg-spin for six and hit another three boundaries to leg.
Early on the Diamonds had caught superbly, but Scott and Heath both spilled simple chances with Dunkley on 85 and 100.
Dunkley was given significant support from England team-mate Freya Davies, who contributed 15 to a ninth-wicket stand of 68.
The Diamonds then showed the value of a good start, with openers Lauren Winfield-Hill and Kalis sharing 88. With the threat of rain around, they eased their way ahead of the Duckworth Lewis Stern rate. Winfield-Hill led the way with 45 off 58 balls, including a pulled six off a Davidson-Richards full toss. As the rain started to fall just before 4.15pm, she chopped on to Macdonald-Gay's seam. But the Diamonds were still ahead of the rate.
Upon the resumption almost half-an-hour later, their position of strength was threatened despite Bess Heath's aggressive 33. She was the first of three quick wickets to fall, including Chloe Tryon's run out for a golden duck, as the score fell to 150 for 5 in the 31st over.
The target later became four off the last over at 174 for 6 and Smith bowling. But Scott lofted her over mid-off to secure a four-point haul.