Kent players celebrate the removal of opener Adam Wheater by Wahab Riaz.
Azhar Mahmood accounted for wicketkeeper James Foster for 17 as Essex were restricted to 153-8.
Joe Denly departed caught-and-bowled for 20.
Rob Key and Azhar Mahmood shared a stand of 97 for the second Kent wicket.
Rob Key led the way with 75 from 52 balls as Kent cruised to 156-2 in 17.5 overs.
Azhar Mahmood saw Kent to the winning post with 50 not out.
Azhar Mahmood bowled Dragons opener Mark Cosgrove after the visitors posted 32 for the opening wicket.
Adam Ball took his third wicket in two games, ending with an impressive 1-19 off four overs.
Skipper Rob Key was disappointed following his dismissal for 18 after an attempted sweep went wrong.
Azhar Mahmood made 32 from 31 balls to keep Kents innings ticking along.
Sam Northeast finished unbeaten on 39 from 25 balls to see Kent to the line.
Geraint Jones hit 30 off 22 balls to see Kent home with four balls to spare.
Sam Northeast and Geraint Jones came together at 85-5 but steered Kent to 142-5 with four balls to spare.
Kent produced two solid displays to record a five-wicket win over Glamorgan on Sunday, hot on the heels of Friday night's eight-wicket cruise against Essex in Friends Life t20.
KM Group Photographer Barry Goodwin was there to capture the action.