Sussex 127 for 4 (Brown 42, Nash 32) beat Hampshire 126 for 9 (Alsop 64, Archer 4-18) by six wickets
Jofra Archer recorded his career best Twenty20 figures to help Sussex end Hampshire's unbeaten start to the Natwest T20 Blast.
West Indian-born fast bowler Archer posted figures of 4 for 18 from his four overs to restrict Hampshire to a below par 126.
And Sussex eased to their first victory of the tournament as Chris Nash and Ben Brown crashed an 82-run stand before Chris Jordan hit the winning runs to complete the six-wicket thrashing with 16 balls to spare.
James Vince won the toss for Hampshire and decided to bat on a grubby looking track as they attempting to celebrate a fourth successive Blast win - but scoring never looked easy for the hosts.
David Wiese hinted at what was to come as he had Rilee Rossouw caught by a diving Jofra at mid-off with the match's fifth ball.
Tom Alsop was the only batsman to appear comfortable for the hosts as he made his first appearance in the competition, and his first-team appearance for Hampshire since May.
He uppercut back to back sixes off the returning Tymal Mills - who was also making his maiden outing this season after IPL commitments and a hamstring problem.
As former England Lions star Alsop appeared in control, wickets fell at the other end.
James Vince swiped across the line to be caught at cover before George Bailey departed to a stunning David Wiese grab while running back at backward square.
Sean Ervine was next to enter and exit when he miscued a pull to square leg as Archer celebrated his first scalp of the evening - Sussex restricting the hosts to 30 for four.
Alsop enjoyed his greatest partnership with fellow academy graduate Lewis McManus as they added 48.
The left-hander moved to his second Blast fifty in 30 deliveries with a crashed pull to the boundary.
Former Hampshire spinner Danny Briggs impressed as he yorked McManus and had Shahid Afridi lbw on the sweep - as he recorded figures of 2 for 17.
But Archer stood out when he finally saw the back of Alsop for 64, caught at short fine leg attempting to scoop an over after being dropped, before he bowled Kyle Abbott.
Reece Topley was the last wicket to fall as the home side could only post 126.
Sussex's reply got off to a poor start as left-armer Topley pinned Luke Wright leg before with an in-swinger.
Runs seemed to flow more quickly in the second innings with Chris Nash and Ben Brown constantly picking the gaps - although the latter was spilled by Bailey on 18.
The carried Sussex to within 42 runs of the win before Brown was lbw for 43 to Afridi.
Nash was caught at mid-wicket for 32 to hand Mason Crane a wicket and Ross Taylor was run out by a Vince direct hit - but Sussex cantered to victory.