Somerset 127 for 5 (Kieswetter 50, Buck 3-25) beat Leicestershire 124 (Thornely 49*, Meschede 4-5, Thomas 3-30) by five wickets
Craig Meschede took his wicket tally in this season's Yorkshire Bank 40 to 20 as Somerset retained the Group C leadership with a five-wicket victory over Leicestershire at Taunton.
The 21-year-old all-rounder confirmed his position as the leading wicket-taker in the competition by claiming 4 for 5 from his five overs as the visitors were restricted to 124 all out after losing the toss in a match reduced to 25 overs per side by rain.
Alfonso Thomas returned 3 for 30 on his return after a hamstring injury, while Michael Thornely played a lone hand with 49 not out.
Somerset made hard work of their target, stuttering to 127 for 5 off 21.3 overs, Craig Kieswetter leading the way with 50 and Marcus Trescothick making 28. Nathan Buck was the pick of the visiting attack with 3 for 25. Leicestershire were never able to gain sufficient momentum after crashing to 49 for 7 by the 13th over.
Steve Kirby and Thomas created pressure with tight opening overs, Thomas removing openers Niall O'Brien and Josh Cobb, the latter having gone into the game with an average of 104 in the competition this season.
Meschede had Greg Smith caught at midwicket with his sharp medium-pace and then switched to the Old Pavilion End to rip the heart out of the middle order by sending back Joe Burns, followed by Shiv Thakor and Rob Taylor with successive balls.
The only resistance came from Thornely, with a little support from Anthony Ireland, who contributed 27 to a ninth-wicket stand of 44.
Somerset lost Peter Trego, the competition's leading run-maker, to Ireland early in their reply, but had moved to 60 in the ninth over when Marcus Trescothick was bowled by a length ball from left-arm seamer Taylor for 28.
Kieswetter, in his first innings since recovering from a thumb injury, looked in good form at No. 3. But he had started walking off when dropped on 32 by Matthew Boyce at deep midwicket off Thakor. He went on to his half-century off 41 balls, with six fours and a six and had put Somerset within 29 of victory when caught behind, edging a cross-batted shot off Buck.
Dean Elgar and James Hildreth also perished to Buck to give Leicestershire a glimmer of hope. But Nick Compton and Alex Barrow batted cautiously to complete the job with plenty in hand, Compton securing victory with a six off Taylor.