At Chelmsford, the home side resumed on 125-1. With Bopara going on to make 133 and John Manders 105, Essex looked comfortable, reaching 247-1.
Then the Warwicks bowlers had the break through and never looked back.
Ian Salisbury started to make the most of his spin, taking the wickets of Maunders, Bopara, Foster,ten doeschate,Masters and Pallindo to record figures of 6-100 and become Warwicks best bowler this season with a 38 wicket total.
With two run outs and wickets for Chris Woakes and Boyd Rankine, Essex were all out for 316 setting Warwicks 143 to win in 45 overs.
Poonia was the first man out for 11 and then Jim Troughton was out for 14 taking the score on to 38-2.
Darren Maddy started to hit runs before John Trott was out for 7. The Skipper went on to make 63 from 98 balls before he wascout with the score on 132-3.
Tony Frost, who broke record after record with his score of 242 in the first innings made 38 and Tim Ambrose made six including the winning runsas Warwicks reached their target with six wickets and six overs to spare.