Glamorgan began their One-Day Cup campaign with a convincing 52-run win as holders Gloucestershire lost their second match in as many days.
Glamorgan built their innings on a 122-run second-wicket stand between Will Bragg (75) and Jacques Rudolph (53).
After Graham Wagg’s 49, the hosts were bowled out in the final over for 289.
Chasing 290 to win, the visitors were eventually restricted to 237 all out, despite Michael Klinger’s 52 and some late stroke play from Benny Howell (77).
Bragg’s aggressive 75 off 68 balls got the scoreboard moving well, while Rudolph’s cautious 53 was his first half-century of the season.
Matt Taylor, Liam Norwell and Howell all bowled intelligently to restrict Glamorgan’s acceleration in the latter stages.
But the target of 290 looked a long way off when Wagg claimed two early wickets and part-time spinner Colin Ingram took two cheap ones in the middle of the innings, including the vital one of Klinger.
Howell’s hitting took the game into the closing overs to make it a fine personal performance, before becoming Timm van der Gugten’s third wicket.
Glamorgan now face Sussex in Cardiff on Wednesday, while Gloucestershire host Middlesex on the same day, still looking for their first win.
The One-Day Cup holders lost their opening game by one wicket to Somerset on Sunday when the home side’s last pair Jamie Overton and Tim Groenewald put on an unlikely 65 to win with three balls to spare.
Glamorgan captain Jacques Rudolph told BBC Wales Sport:
“We were quite clinical in the way we went about our business. William Bragg batted outstandingly but we were 15-20 runs short of where we could have been.
“I just wanted to spend some time in the middle. That’s important when you’re not performing as well as you’d like and I was fortunate to bat with Braggy who’s in very good touch.
“Our bowlers were very good. Colin Ingram bowled exceptionally, as well as Timm van der Gugten.
At the moment we’ve got some good momentum in white-ball cricket. If that can continue for the rest of the week I’ll be a happy captain.”
Gloucestershire captain Michael Klinger told BBC Radio Bristol:
“Last year we won seven out of eight. There’s no reason why we can’t win five out of six now but we need to do the little things a bit better, particularly in the field.
“We got out-worked because they out-fielded us and bowled really well to their field.
“It’s tough not having Jack Taylor to bowl. Either we need the guys we’ve got to bowl better or we need to change the line-up.
“It’s disappointing. We need a collective effort and so far we haven’t had that.”