Gloucestershire strolled to a chase of 148 to beat Kent by eight wickets with fully 38 balls to spare on a golden evening at Bristol.
It was their third win of the competition and just a second defeat for Kent, who remain top of the South Group.
Some of the home side’s delight was taken away by an ankle injury to Ian Cockbain, who retired hurt on 30, but the game was so easily won and their net run-rate was given a big boost.
Miles Hammond gave the chase the perfect start, striking the first two balls over cover for four and then the first two of the fourth for six over square leg. But he miscued another pull and was caught for 33, his best return in the tournament so far.
Chris Dent also swung a mighty six over deep square in the second over and lifted four more over mid-on before helping take 21 from the final over of the Powerplay bowled by Grant Stewart.
He began with a six over long-on before swinging six more over midwicket from a no-ball. He chopped four past point and at the end of the Powerplay, Gloucestershire were 75 for one and the required rate was only five-an-over.
Dent fell for 37 in 21 balls before Glenn Phillips saw his side home with an unbeaten 41 from 25 balls, finishing the game with a switch-hit six.
Kent, having been sent in, were given a bright start with Zak Crawley’s 43 from 29 balls. He flicked Dan Worrall over midwicket for six in the opening over and clubbed another maximum, also mistimed, in the fifth over.
He targeted the short leg-side boundary again off Benny Howell for a third six before a top-edge, on 34, landed between two converging fielders. He survived to strike Tom Smith down the ground for four but top-edged a sweep to Worrall at deep square.
Crawley dominated the opening 10 overs where Kent made 74 for three. Daniel Bell-Drummond tried to paddle-sweep Josh Shaw and lost his middle-and-off stumps for 11 and Joe Denly, becalmed on five from nine balls, slapped Howell straight to extra-cover.
Jordan Cox played a most-necessary late hand with 36 in 28 balls, including scooping Worrall over deep-square for six, but the target proved well short.
Gloucestershire’s Jack Taylor:
“A great win, pretty much the perfect performance that we’ve been after.
“We strung it all together, had pretty much the perfect bowling performance and caught almost everything.
“With the bat we were clinical and had guys there at the end.”
Kent’s Zak Crawley:
“They played really well to be fair to them and showed us how to play on this type of wicket.
“In the southern group you get a lot of good wickets but this was a bit slow and we have to be a bit better on this type of wicket.”