Somerset 220 for 2 (Thomas 106*, Rew 60*) beat Lancashire 218 (Green 65, Bell 56, Aldridge 6-33) by eight wickets

In reply, the hosts raced to 220 for 2 off 40.5 overs, Thomas leading the way with an unbeaten 106 off 142 deliveries, with 14 fours and two sixes. James Rew contributed 60 not out and Lewis Goldsworthy 38 to inflict Lancashire's fourth defeat in as many group matches.

They never gained much momentum to their innings after a cautious start against the impressive Alfie Ogborne, which saw Bell and Harry Singh put together an opening stand of 47, ended in the 13th over when Singh was bowled by Jack Leach aiming a forcing shot through the leg side.

It was 79 for 2 in the 20th over when Thomas bowled visiting captain Josh Bohannon playing down the wrong line. Bell went to fifty off 72 balls, but the tempo of the innings was never fast enough on such a quick-scoring ground.

Balderson was caught and bowled by Goldsworthy off a leading edge for 27 and Aldridge had IPL winner Venkatesh Iyer caught by the diving Sean Dickson at cover as Lancashire slid to 121 for 4.

Bell chipped a catch to mid-on off Aldridge and Rocky Flintoff gave Goldsworthy a second caught and bowled before Aldridge sent back Jack Blatherwick and Tom Aspinwall with successive deliveries, forcing Mitchell Stanley to face a hat-trick ball on his List A debut. He survived it before falling to a stunning catch by Leach, diving full length on the run from mid-off as two team-mates converged on him to give Aldridge his fifth wicket.

Green blasted four fours and four sixes and shared a last-wicket stand of 51 with Charlie Barnard. But when he also skied a catch off Aldridge in the final over Lancashire looked well short of a competitive total.

So it proved, as despite losing Andy Umeed early in their reply, Somerset attacked the meagre target with gusto, Thomas and Goldsworthy producing a boundary blitz that took their team to 64 for 1 by the end of the tenth over. The score had extended to 73 when Goldsworthy was bowled leg-stump by left-arm spinner Barnard in his opening over.

Thomas slog-swept a six off Barnard in moving to a 79-ball half-century and soon celebrated with a pulled six off Aspinwall. He found a reliable partner in Rew, who gradually found his timing to join in the glut of boundaries.

Thomas was given a life of 77 when dropped at long-on by Stanley off Green before bringing up the century stand with Rew by sweeping a four off Barnard. The Taunton-born 20-year-old went to three figures with a single off Green, raising both arms in celebration before turning to hug Rew, who seemed equally delighted for his friend and team-mate.

A handsome cover-driven four off Blatherwick took Rew to a 56-ball fifty as the stand with Thomas became a Somerset List A record for the third wicket against Lancashire, beating the 118 put together by a certain Ian Botham and Vivian Richards in a 40-over game at Bath in 1978.