Somerset continued their perfect start to the Vitality Blast after Josh Davey put on a bowling clinic against Hampshire at the Ageas Bowl.
Davey claimed three wickets in the match - his second such haul in two days - reducing the Hampshire Hawks to 123.
That was a total that was easily within Somerset's grasp, despite slipping to 89 for five at one stage.
However, Tom Lammonby scored a classy 33 to steady the ship as the visitors got over the line with 25 balls to spare.
Somerset, runners-up last year, had already beaten holders Kent and 2019 winners Essex and now sit level on points with Middlesex at the top of South Group.
Hampshire, who lost to Somerset in last year's semi-final, sit bottom with two home losses in two games.
Aneurin Donald, Ben McDermott and Joe Weatherley were all caught out in the powerplay as Hampshire slipped to 38 for three.
Somerset produced a fine all-round bowling display. Lewis Gregory recorded two for eight and Marchant de Lange two for 20, while Ben Green also worked hard in the middle overs for his two for 19.
They were helped by some excellent catching, not least Tom Lammonby and Will Smeed's relay catch to dismiss Chris Wood.
James Fuller was the only counter-attacker as he scored 42 from 28 balls, including two massive sixes over midwicket, but no other Hampshire batter reached 20 in a below-bar batting effort.
Smeed and Tom Banton piled further misery on the hosts with a 46-run partnership for the first wicket - the highest stand of the game.
Australian recruit Nathan Ellis endured a horror first over, which saw two no balls, a huge Smeed six and 17 runs.
Smeed and Bantom fell in successive overs, carving Fuller to cover and nicking Wood behind respectively.
Rilee Rossouw returned to the Ageas Bowl, where he spent three seasons as a Kolpak, to strike a six off his legs, but he, Tom Abell and Gregory all fell within 12 balls of each other to give the hosts hope.
But Lammonby then struck 33 to ease those worries and despite edging Ellis behind with two runs to win, Somerset quickly reached the target.