An assured 116 from Alex Hales proved in vain as Essex pair James Foster and Matt Walker responded with great poise to condemn Notts outlaws to a seven-wicket defeat.
Notts had registered 287-7 after winning the toss and batting and had every reason to be confident of defending a decent total that had been held together by a fine knock from in-form Hales who asserted himself with 12 fours and 3 sixes before lofting one to Adam Wheater.
His partnership with Samit Patel was particularly fruitful with 124 runs added before Patel’s dismissal. Notts were 150-1 after twenty overs but Patel’s wicket was quickly followed by those of Voges (4) and Mullaney (10).
Chris Read’s 23 was useful whilst Scott Elstone finished unbeaten on 35 but Sam Wood had an unhappy baptism on his first team debut when he was run out without facing a ball.
Essex were able to name an experienced top five with England duo Alistair Cook and Ravi Bopara adding 110 runs for the second wicket.
Cook notched 96 before he was bowled by Luke Fletcher and Bopara was caught by Neil Edwards at long-on for 50.
Notts remained in the hunt with the hosts required to maintain a rate just shy of ten an over with ten remaining. Their wickets in hand allowed James Foster and Matt Walker to play positively to secure victory with an over to spare.
Foster hit 66 from 44 in a century partnership with Walker who found the boundary seven times in his rapid 45.
Notts will hope to register a first Clydesdale Bank 40 win of the season when they face the Unicorns at picturesque Wormsley on Sunday 15 May.