Hampshire 155 for 6 (Weatherley 42) beat Essex 142 (Westley 44) by 13 runs
Chris Wood lead a superb defensive bowling display as Hampshire Hawks beat Essex Eagles by 13 runs to get their Vitality Blast competition rolling.
Left-arm fast bowler Wood's four overs went for just 15, along with the scalp of Aron Nijjar, with fellow homegrown star Liam Dawson returning a miserly 1 for 17.
Joe Weatherley top-scored with 42 as the Hawks struggled to 155 but despite Tom Westley's 44 the Eagles were bowled out for 142 - losing their last five wickets for 22 runs.
Hampshire were stuck in and were contained well by the Essex bowlers as they reached 39 for the loss of James Vince - aggressively pulling Sam Cook to midwicket - in the powerplay.
Simon Harmer, for the second match in succession, struck with his second delivery to york Tom Alsop.
Cook took career-best T20 figures against Somerset and once again impressed with analysis of 2 for 21 as he had Australian D'Arcy Short caught behind by Will Buttleman - leaving the visitors 59 for 3 in eight overs.
Weatherley rebuilt with Dawson and James Fuller through 35 and 33-run stands without any explosion to the run rate.
Dawson was stumped off Harmer and Weatherley - having notched 42 from 34 balls - picked out deep midwicket to leave Hampshire facing a below-par total.
But James Fuller plopped Jamie Porter for back-to-back sixes back over his head at the River End in the penultimate over to boost the tally, before he skied to cover.
Buttleman lasted only seven balls on debut before he hooked Brad Wheal to fine leg.
Michael Pepper also departed in the powerplay, caught behind attempting to sweep Dawson, as Essex reached 41 in the first six overs.
The impetus was raised as Paul Walter lifted Mason Crane for sixes into the Hayes Close End houses from the first over of the leg-spinner's first two overs.
Westley also lofted over the straight boundary, but Crane got the last laugh, and loud grunting send-off, as Walter danced past a straight one to be stumped, before Westley was run out by a Ian Holland direct hit.
Ryan ten Doeschate was bamboozled by Crane, struggling for four dots before slicing to short third man - as the England spinner pulled back his first 13 balls going for 37 to end up with two for 42 from his four overs.
Jimmy Neesham clubbed Wheal into the Doug Insole Pavilion with a pull to accompany some powerful fours but he was caught at midwicket with 36 still needed.
Nijjar pulled to deep fine leg, Simon Harmer and Sam Cook were run out and Plom was bowled by Wheal to confirm the victory.