Hampshire 160 for 7 (Dattani 31, Coppack 4-18) beat Essex 137 for 9 (Grewcock 57*, Dattani 2-24) by 23 runs
Hampshire Hawks' spinners shared figures of 5 for 74 to strangle Essex and secure a first Vitality Blast women's competition victory of the season.
Bex Tyson, Georgia Adams and Amanda-Jade Wellington's 12 combined overs went at barely a run a ball with regular wickets to help defend 160.
Kate Coppack's exceptional 4 for 18 had kept the Hawks to around par - with Naomi Dattani top scoring with 31.
But despite the newly capped England all-rounder Jodi Grewcock hitting a half-century, Essex fell short by 23 runs.
On three occasions during the Hampshire innings, Coppack throttled the Hawks - who had chosen to bat first - with unrelentingly accurate bowling.
Firstly, in the powerplay, where her two overs went for nine runs, with the added bonus of having Georgia Adams caught at midwicket. It contributed to only 35 runs coming in the first six overs.
Her third over saw her bowl Francesca Sweet - who had looked dangerous with a quickfire 20 - and only went for four runs.
And her final return, in the penultimate over of the innings, ended Hampshire's most fruitful partnership - 45 from 28 balls between Rhianna Southby and Nancy Harman. Coppack dismissed both of them in the over to complete an impressive 4 for 18.
Around Coppack's flattening, the Hawks built a solid score, with every batter getting a start and plenty of partnerships getting formed, but none kicking on to help set an imposing total.
Amanda-Jade Wellington and Poppy Tulloch, combining for 21 runs off the final seven balls gave the hosts some momentum.
Essex had scored 76 runs in the powerplay in their win over Warwickshire Bears on Friday night but had the opposite experience when they could only muster 28 at Utilita Bowl.
That was largely down to Naomi Dattani dismissing both Eagles openers caught in the fourth over.
But Cordelia Griffith and Grewcock laid down a platform with a 71-run stand as they tried to catch up but they couldn't make the most of it as they slumped in the second half of their innings.
The trio of spinners locked things down, stemmed the runs and with regular wickets, made sure of the home win, as Grewcock's third T20 fifty was in vain.
Adams boasted the best of the figures with 2 for 26, with Wellington 2 for 27 and Tyson miserly in 1 for 21.
