Hampshire's bowling attack impressed but Somerset's Johann Myburgh struck an excellent half-century to see Somerset come out on top against James Vince's side at the Ageas Bowl.
Liam Dawson was the pick of the bowlers as they tried to defend a modest total, with the spinner picking up superb figures of just 1-14 from his four overs.
The returning Dale Steyn, who made his Hampshire T20 debut, also impressed with the ball as he claimed 1-21 from his allotted overs.
However, opening batsman Myburgh found the boundary regularly to help his side chase down 129 with six wickets in hand.
He added 32 for the first wicket with Steven Davies, who was brilliantly caught in the covers by a diving Dawson.
Myburgh was unfazed by the loss of partner as he got his head down and kept the run rate ticking at just above the six and over needed.
Peter Trego was deceived by a Mujeeb Ur Rahman variation, as he played on, and James Hildreth hit straight up in the air to be caught keeper Tom Alsop, but Myburgh remained comfortable.
Myburgh moved to his 11th format fifty and although Liam Dawson had Corey Anderson lbw, eased Somerset to a six wicket victory with seven balls to spare.
Earlier, Lewis Gregory won the toss and elected to bowl on the same wicket that Southern Vipers had posted 159 earlier in the day – a quickish wicket, which slowed throughout the two games, albeit with steady bounce.
Despite James Vince firmly cutting Max Waller through point first ball and Rilee Rossouw dispatching a six over cow corner, wickets fell with regularity.
Hampshire were left 45 for two at the end of the powerplay and quickly lost Tom Alsop skying to mid-wicket and Liam Dawson offering up a simple catch at point.
Sam Northeast attempted to anchor an end – scoring 30 off 36 balls – but nobody else could build around him.
The right-hander eventually fell off a top edge, before Joe Weatherly was bowled.
Steyn rounded out the innings by striking a boundary as Hampshire posted 129 for eight.
Words: Press Association