Hampshire 188 for 3 (Vince 81, Roussouw 46) beat Sussex 169 for 7 (Wright 3-50, Abbott 3-22) by 19 runs
Two Sussex-born players returned to the county and played key roles as Hampshire made it two wins out of two in the NatWest T20 Blast at Hove.
Cuckfield-born James Vince's 81 was the cornerstone of the visitors' imposing total of 188 for 3 then leg-spinner Mason Crane, born in Shoreham and educated at Lancing College, removed Sussex's big guns Luke Wright (50) and skipper Ross Taylor (27) during his spell of 2 for 24.
David Wiese hit out towards the end but Sussex finished on 169 for 7 and lost by 19 runs, their second successive defeat.
Hampshire's imposing total on a slow wicket was set up by an opening stand of 109 between Vince and South African Rilee Rossouw.
Vince looked in good touch from the start, hitting four successive boundaries off Jofra Archer in the third over as the visitors raced to 102 at the halfway stage of their innings.
Rossouw was impeded by an ankle injury but still clobbered three sixes and four boundaries in 46 from 31 balls before he holed out in the 11th over.
Sussex dragged things back slightly with Hampshire adding just 14 runs between the 10th and 14th overs but Vince looked on course for a hundred when Archer returned to the attack and yorked the left-hander in the 16th over. Vince's 81 came from 48 balls with ten fours and three sixes.
Momentum was provided towards the end by Michael Carberry with 41 from 30 balls after Shahid Afridi, promoted to No.3, gave Chris Jordan a deserved wicket.
Sussex lost opener Chris Nash after he had put on 33 for the first wicket with Wright during an excellent opening spell by Kyle Abbott. Ben Brown, promoted to No.3, fell cheaply but Taylor and Wright came together to put on 49 in 6.1 overs and at halfway Sussex were keeping tabs with the required rate.
Wright, who made 101 in Sunday's opener against Glamorgan, reached 50 with three fours and three sixes but two balls after getting there he was caught at long off by the diving Rossouw and in the next over Crane lured Taylor (27) down the track trying to hit through mid-wicket and Lewis McManus pulled off a smart stumping.
His dismissal left Sussex needing 82 off seven overs and although Wiese muscled three sixes and Laurie Evans two in a stand of 47 from 27 balls they could not maintain the tempo. Evans drove Abbott's slower ball to extra cover and Sussex's race was run when Wiese was caught at long off from the first ball of the final over.
Abbott finished with 3 for 22 and bowled superbly but it was the performance of the two Sussex-born players which most hurt their home county.