Friends Life t20, Chelmsford (1900 BST)
Essex (146-5) beat Glamorgan (144-9) by five wickets.
Tim Southee returned the best T20 figures by an Essex bowler as Glamorgan lost by five wickets at Chelmsford.
The paceman took a hat-trick in a four-wicket final over to finish with 6-16 and restrict Glamorgan to 144-9.
Essex needed 49 from their final five overs, but Scott Styris hit 42no from 21 balls to ensure victory with five balls to spare.
Southee's performance almost matched Somerset's Arul Suppiah's t20 record of 6-5, also achieved against Glamorgan.
BBC Wales Cricket correspondent Edward Bevan:
"Another defeat, another last over finish. But for the second game in succession this was a spirited effort from Glamorgan's young and inexperienced team.
"The only blemish was the batting, where a total of 144-9 was under-par on a good pitch with small boundaries. Tim Southee took six for 16 for the home side, including the hat-trick.
"Gareth Rees and Stewart Walters made 38 and 37 respectively and when Essex batted, they were restricted by some effective bowling.
The home side needing nine an over from the last four but Scott Styris blasted 42 not out from 21 balls to see them through."