Peter Trego blasted 81 in a hurry to help Somerset chase down a target of 251 with three wickets to spare against the Welsh Dragons at Taunton.
All-rounder Trego made the most of being dropped by Simon Jones with just five to his name, hammering a six and 15 fours in the Group B clash of the Clydesdale Bank 40.
His efforts, along with contributions from Nick Compton (53) and Lewis Gregory (39), made sure Chris Cooke's superb unbeaten century for the visitors would be in a losing cause.
The 26-year-old South African hit four sixes and 11 fours in his superb 137 not out, inspiring the Welsh county to a competitive total of 250-9.
However only Stewart Walters (34) offered any real support, the former Surrey batsman helping add 84 for the fourth wicket.
Cooke was missed by Alfonso Thomas off his own bowling on 108, allowing him to go on and add a further 29 runs to his total as 49 came off the final five overs.
Steve Kirby and Trego both claimed three wickets apiece for Somerset, though the latter made a more telling impact with the bat in his hand.
The 31-year-old needed just 26 deliveries to reach his half-century, and he looked on course for a remarkable ton before pulling a ball from spinner Dean Cosker straight to Jim Allenby at mid-wicket.
Compton and Gregory put on 60 but neither man was able to see the job through to the end, meaning Craig Meschede - who had damaged a finger in the field - had to come out and see Somerset over the line.
The injury didn't stop the young all-rounder hitting a straight six off Allenby, before team-mate Thomas sealed victory with a boundary off the same bowler from the penultimate ball of the 38th over.