Peter Trego's blistering 81 off 43 balls set Somerset on course for a three-wicket Clydesdale Bank 40 victory over Welsh Dragons at Taunton.
The hosts chased down a target of 251 with 13 balls to spare, Trego dominating an opening stand of 92 with Marcus Trescothick, who contributed only 14. Nick Compton hit 53, while Dean Cosker took two for 37.
Chris Cooke's superb 137 not out, including four sixes and 11 fours, had inspired the visitors to a challenging 250 for nine. But the 26-year-old South African lacked support, with only Stewart Walters (34) contributing to a significant partnership.
Trego claimed three for 45 before his explosive batting, while Steve Kirby picked up three for 43 as the home seamers varied their pace cleverly.
Cooke totally dominated Glamorgan's innings, giving just one chance on 108 when Alfonso Thomas dropped a return catch. Even at that late stage it proved an expensive miss as the batsman went on to add 29 to his score as 49 came off the last five overs.
Only Walters gave Cooke much support, the pair adding 75 for the fourth wicket in good time before Walters became the third Glamorgan batsman to perish to a leading edge, caught at cover off Thomas.
With wickets falling regularly at the other end, Cooke had to rein himself back, but he still cleared the ropes four times, including a glorious strike over mid-wicket off Thomas in the final over, in reaching his first ton for the Dragons.
Somerset had two of their players taken to hospital during the Glamorgan innings. Craig Meschede damaged a finger, while substitute fielder Alex Barrow was briefly knocked out when crashing head first into an advertising board when trying to prevent a boundary, but recovered in the treatment room.
The hosts' fielding was below par with a number of fumbles. But there was nothing indecisive about their batting as Trego went ballistic after being dropped by Simon Jones off his own bowling at the start of the second over.
The powerful batsman needed only 26 balls to reach a half century, with 11 fours, and immediately celebrated with a straight six off Cosker. He looked on course for a remarkable ton before pulling a ball from Cosker straight to Jim Allenby at mid-wicket.
After James Hildreth fell cheaply, Jos Buttler (27) helped Compton ease Somerset towards their target before Lewis Gregory's 39 kept them ahead of the required rate.
Meschede had to bat at the end, despite his injured finger, which didn't stop him hitting a straight six off Allenby, before Thomas sealed victory with a boundary off the same bowler.
