Glamorgan 201 for 6 (Meschede 77*, Howell 3-39) beat Gloucestershire 199 for 9 (Taylor 52, Hogan 3-31, van der Gugten 3-54)
There was a pulsating finish at Sophia Gardens, where Gloucestershire, mainly through the efforts of Jack Taylor, got within three runs of beating Glamorgan.
AJ Tye, having hit the previous ball for six, missed the last, and Timm van der Gugten, having also dismissed Taylor earlier in the over, was Glamorgan's hero. Glamorgan gained their fourth win, while the visitors were deposed at the top of the southern Group.
Glamorgan scored 201 for 6, with Craig Meschede reaching a career best 77 not out from 47 balls, which included five sixes and four fours, and setting the visitors a testing target which required them to score at ten runs an over.
They made a brisk start and were helped by a five-run penalty when a Glamorgan fielder was penalised for "pretending to field the ball" but the home team were soon in control as Gloucestershire lost three wickets in quick succession.
Miles Hammond lifted Michael Hogan to long-on, then Michael Klinger and Ian Cockbain were out to successive deliveries. Klinger was well held by Hogan at long-off, then Cockbain nicked one from Rory Smith to the wicketkeeper. Benny Howell struck Smith for two sixes in the seamer's final over, but when Graham Wagg was brought on, he bowled Howell with his first ball.
Wagg was then struck a fierce blow on his head, attempting to get in the way of a drive from Ryan Higgins from the fifth ball of his second over, and although was reluctant to leave the field, common sense prevailed.
Gloucestershire needed 75 from the final five overs, and a rapid 57-run stand between Taylor and Higgins gave them a flicker of hope. Higgins perished to Hogan, and Noema-Barnett also fell to the same bowler.
But Taylor kept on swinging, and with sixteen runs needed from the final over, van der Gugten held his nerve to bowl Taylor for 52 from 21 balls, but when Tye swung the bowler for six, nine were needed from three balls, and three from the last ball.
After they were put into Usman Khawaja, playing his final game for Glamorgan before returning to Australia, and Aneurin Donald opened for the home team with Donald soon into his stride, striking Higgins for six and four in the bowler's opening over and then driving Tye for another six as the Australian conceded 17.
After driving David Payne for a straight six, the bowler got his revenge two balls later when Khawaja player on to a full delivery after sharing an opening partnership of 45 in five overs.
Donald was joined by Meschede, who struck Howell for three successive fours as Glamorgan ended the Powerplay on 60 for 1. The second-wicket pair added 37, before Donald, who scored 31 from 27 balls, was caught attempting the ramp shot off Howell.
Kiran Carlson, who top scored in Glamorgan's win against Surrey earlier in the week, struck a six to get off the mark, but after driving Tye to the boundary, was out the next ball when he skied to extra cover.
Chris Cooke, leading the Glamorgan team in the absence of Colin Ingram, then settled into productive partnership with Meschede, scoring a brisk 29 in a stand of 50, before he was caught at midwicket.
Glamorgan then lost two wickets for one run, as Wagg was leg before to Howell first ball, and Andrew Salter was caught behind, but Meschede kept Glamorgan going with a series of attacking strokes.
Tye, one of the best T20 bowlers in the world was struck for 25 in his final over as he ended with 4-0-50-1