Essex 181 (Pettini 68, Smith 3-26) beat Gloucestershire 163 for 7 (Klinger 104*, Napier 3-30) by 18 runs
Despite another fine innings by Michael Klinger, Essex gained sweet revenge for their defeat at Bristol last month by beating Gloucestershire by 18 runs in their NatWest Twenty20 Blast South Group clash.
Klinger, who scored an unbeaten century in that first meeting, made his presence felt again with 104 not out - but it was not enough to save his side from defeat as they replied to Essex's 181 with 163 for 7 at Chelmsford.
Graham Napier played an important part in Gloucestershire's woes with some hostile bowling that brought him three wickets for 30 runs from his four overs - and he received good support from off-spinner Tom Westley (2 for 27).
Klinger was left ploughing a lone furrow as he completed his half-century from 32 balls - he was unable to call upon meaningful support as wickets tumbled at regular intervals around him.
He moved into three figures with an on-driven six at the expense of fellow Australian Shaun Tait , one of three such massive blows in an innings which also brought him 10 fours. In all he faced just 64 deliveries while gathering his second unbeaten century in successive matches against the Essex attack.
Gloucestershire fell well short of their target as Essex claimed their third victory in this season's competition to keep alive their hopes of reaching the quarter-final stage.
They had been given a super start by opener Mark Pettini, who shared in an opening stand of 46 in 4.1 overs with Jesse Ryder and one of 68 in eight overs with Westley.
Essex had look set for a much more formidable score when they reached the halfway stage on 98 for 1 but they managed only 28 in their next five overs, during which they lost three wickets. One of those was Pettini, stumped by Geraint Jones off Kieran Noema-Barnett for 68 from 44 deliveries - including 10 fours and a six.
Essex were then revived by James Foster and Napier, both of whom struck two sixes in their efforts. Left-arm spinner Tom Smith had halted the home side's progress by removing Westley, Ravi Bopara and Nick Browne at a cost of 26 runs in his four overs.
James Fuller and David Payne, with two for 22 and two for 25 respectively, were the visitors' other main wicket-takers in a match watched by a near-capacity crowd of around 5,000.