Glenn Phillips slammed an unbeaten 94 from just 41 balls to power Gloucestershire to victory by 34 runs over Glamorgan at Bristol, sending them top of the South Group.
Phillips’ fifth-highest score of his career, and first half-century in the Vitality Blast, powered Gloucestershire to 216 for two - their own fifth-highest T20 total.
He struck nine fours and six sixes to overwhelm Glamorgan, who gave game chase for a while but could only reply with 182 for eight.
Phillips and Benny Howell, promoted to three in place of the injured Ian Cockbain, shared 130 for the third wicket in 64 balls - a record T20 partnership for Gloucestershire’s third wicket.
Phillips arrived after Miles Hammond and Chris Dent had given the innings a lively start after losing the toss, making 60 without loss.
He cut Marnus Labuschagne through extra-cover before lifting Dan Douthwaite over the sight screen. He blasted Prem Sisodiya twice straight back past his for four and swept him fine for another boundary in going to fifty in 26 balls.
He took 14 from the 17th over, clubbing Tim van der Gugten over long-off, before uppercutting Douthwaite for a third six. An extraordinary reverse-scoop flew over third man for six as 23 came from the 18th.
In the final over, he launched van der Gugten over the longest boundary at midwicket, crashed him wide of deep cover for four and swung the final ball of the innings over deep-square.
Howell took his chance up at three to make an unbeaten 53 in 33 balls. He struck Callum Taylor for four through extra cover and wide of midwicket before a slug down the ground cleared long-off for six. He drove Weighell for four to raise a fifth T20 half-century.
Glamorgan needed their third-highest T20 total to win and stayed in the game for the first half of the chase.
David Lloyd gave them a rattling start with 44 in 22 balls, striking four sixes, three of them short-arm jabs over midwicket and Glamorgan reached 101 for four at halfway. But Tom Smith then bowled two overs for nine and then a wicket maiden to leave 15-an-over for the final five.
Labuschagne was, as ever, a crucial wicket and Payne yorked him walking across his stumps. 33 in 21 balls was well light of what Glamorgan needed.