Neil Carter took 3-23 as Champions Worcestershire were reduced to 175 all out.
Warwickshire,who will play in the second division of the competition next season had Ian Westwood hit 39,Jon Trott 37 not out,Alex Loudon 36 and Tim Ambrose 31 not out to win with twelve and a half overs to spare.
Warwickshire finish second bottom of the table ahead of Essex with both teams having five points.
England were beaten by South Africa in the Twenty/20 World Cup by 19 runs.