Hampshire skipper Nic Pothas kept his cool to scramble a winning single off the final ball against Sussex to get his side off the mark in the Twenty 20 Cup under the Hove floodlights.
Hampshire squeezed home by six wickets before a sell-out crowd of 7,000 after Sussex Sharks posted 204 for six - their second-highest score in the competition.
Pace bowler James Kirtley had an opportunity to run out Pothas as the ball was played down the pitch, but his throw missed the stumps at the bowler's end.
The visitors, who needed eight off Kirtley's final over, were indebted to Zimbabwean Sean Ervine who - despite batting with a runner due to a hamstring injury - thrashed 38 not out off only 20 balls with two sixes and four fours.
Ervine shared in an unbroken match-winning stand of 46 for the fifth wicket in his four overs with Pothas (10).
Michael Carberry led Hampshire's victory bid with a bold 58 which came off 29 balls and included seven fours and three sixes.
Sussex's testing target was built around Murray Goodwin's 69 and a blistering 72 from only 27 balls from Dwayne Smith.
Smith hammered four fours and six sixes in his highest score in the competition.
He guided the Sharks to their challenging total by adding 56 in seven overs for the fourth wicket in partnership with Goodwin, who fired nine boundaries in his 57-ball innings.
Goodwin, whose knock ended when he pulled Nantie Hayward to mid-wicket, shared a second wicket stand of 54 in seven overs with Chris Nash, who was trapped leg before by Greg Lamb for 15.
Sharks skipper Chris Adams (13) also fell to off-spinner Lamb after adding 29 in two overs with former Zimbabwe star Goodwin.
Michael Lumb, dropped on 19 off Corey Collymore, gave Hawks a fine start by firing 36 in an opening stand of 48 with Ian Harvey.
Smith suffered in his opening over with Carberry hoisting him for six over mid-wicket before following up with two successive boundaries.
But West Indian all-rounder Smith - signed for the duration of the competition while Mushtaq Ahmed recovers from a knee injury - ended a second-wicket stand of 41 between Carberry and Harvey by bowling the latter for 29.
Carberry reached his half century in style off only 22 balls by lifting Michael Yardy for his third six over long on.
Hampshire needed 46 from the final four overs when Carberry was brilliantly caught by Yardy at wide mid-off to give spinner Rory Hamilton-Brown his second wicket and narrowly negotiated the chase.