Australia star Alyssa Healy’s blistering 31 looked to have put Yorkshire on top in their pursuit of 131, after Helen Fenby helped restrict Surrey by claiming four wickets.
But the Diamonds, who have yet to reach Finals Day in the KSL, failed to capitalise on their strong start as Laura Marsh took three wickets to lead the Stars to an opening day success.
Healy, who scored 266 runs in the women’s Ashes, launched a superb attack in the powerplay, striking three boundaries in each of the third and fourth overs.
But she was removed for 31 from 17 balls by spinner Mady Villiers – who also dismissed the 29-year-old on her England debut last week – to leave Yorkshire 43-1 in the fifth over.
Experienced England spinner Marsh helped keep the Diamonds in check with two key wickets.
Hollie Armitage and India star Jemimah Rodrigues fell for 12 and four respectivel but Yorkshire reached 75-3 at the halfway mark as captain Lauren Winfield set about anchoring the innings.
Stars captainNatalie Sciver dismissed Cordelia Griffith for five and then claimed the key scalp of Winfield for 31.
At 97-5, Yorkshire required 34 to win from the last five overs. But Leigh Kasparek fell in the 16th as Marsh claimed 3-17 from her four overs.
All-rounder Alice Davidson-Richards offered hope for the Diamonds with a brisk 17, taking them to 19 needed from 12 balls, but her run out in the 19th over ended their chances.
Yorkshire lost three wickets in the final over to be bowled out for 121.
Surrey’s innings had followed a similar pattern. South African Lizelle Lee, who hit 104 from 58 balls in last year’s final win over Loughborough, hammered two fours in the opening over.
But Lee was the first of four wickets for 20-year-old leg-spinner Fenby, trapped lbw for nine attempting to sweep, before opening partner Bryony Smith was caught by Armitage for a breezy 20.
England pair Sarah Taylor and Sciver guided Surrey to 71-2 at the halfway mark, with the latter striking the only six of the match as she crashed Kasparek down the ground.
But the Edinburgh-born New Zealand spinner quickly got her own back when she forced Sciver to miscue one straight back to her.
Taylor, who missed the T20 part of the recent women’s Ashes due to mental health problems, played well on her return to make 43.
But her departure in the 15th over, also caught and bowled by Kasparek, sparked a collapse.
The leg-spinner picked up her third when South African Dane Van Niekerk was brilliantly caught in the deep by Rodrigues, before Marizanne Kapp was the third to be caught and bowled – this time by Linsey Smith.
Fenby returned to dismiss Marsh and Gwen Davies to finish with 4-20, but Surrey’s total of 130-9 was beyond Yorkshire.