On a gorgeous day in Birmingham, Warwicks batted first and had Ian Bell as the mainstay of the innings. Bell hit eleven fours in his 108 and was backed up by Stratford's Jim Troughton who made 53 which included the only six of the Warwickshire innings.
Barker made 28 with Chris Woakes adding 25 whilst opener Jon Trott made 13 with Clarke and Botha both adding 14 each.
Warwicks had struggled against Somerset in their County Championship match when bowling and the same happened today.
Kieswetter made an unbeaten 138 for the visitors as they raced to the total with only the wickets of Trescothwick and Hildreth down and four overs of the fifty to spare.
On Wednesday, Warwicks take on Hampshire in a four day County Championship game at Edgbaston.