Warwicks won the toss and put Scotland into the bat at Edgbaston. Scotland who beat Leicestershire last week, started well against the Warwicks attack and it was not until Scotland had passed the fifty mark that the first wicket came when Hairs became the first victim of Keith Barker.
Barker bowled Watts for 24 and had Parker caught to see Scotland on 69-3in the 15th over.
George Bailey and Richie Berrington were in fine form, adding 198 for the fourth wicket with Bailey making an unbeaten 123 which included five sixes and nine fours and Berrington who became Barker's fourth wicket making 82.
Scotland ended their forty overs on 267-4.
Warwickshire knew this was a large target on their current form and it was a job made more difficult when Varun Chopra was out after only making two runs.
Neil Carter and Keith Barker added 101 for the second wicket before Carter, who had hit three sixes and eleven fours from 62 balls was caught by Watts off the bowling of Lyons.
Six runs later, Lyons got a second wicket when Barker was out for 40 and then he added a third with the wicket of Troughton who scored ten.
With Ian Westwood only adding five runs to the total, Warwickshire were falling behind on 156-5 in the 24th over.
Darren Maddy and Rikki Clarke came together and put together a good knock of 112 which took Warwicks level on runs scored. Maddy had made 74 before he was caught by Lyons was the man out and it was left to Rikki Clarke who finished on 49 not out to see Warwicks to a four wicket victory.
Tomorrow, Warwickshire are in County Championship action when they take on Kent at Edgbaston. Play is due to start at 11am.