Joe Leach hit a spectacular 63, and there were half-centuries from captain Jake Libby, and keeper Ben Cox as Worcestershire Rapids went down fighting by 19 runs to Glamorgan in a high-scoring Royal London Cup encounter at New Road.
Glamorgan had been indebted to centuries from Sam Northeast and Billy Root as they totalled 356-3 from their 50 overs.
But the Rapids, who had won their previous two games against Northamptonshire and Essex, made a brave reply.
Leach’s big-hitting knock was the highlight, while Libby and Cox, who ended undefeated on 84, completed their third fifty-plus scores in the tournament.
They eventually closed on 337-9 in a day which produced almost 700 runs.
The Rapids handed a senior debut to Scotland international spinner Olly Davidson, the third member of their 2021-2022 Academy intake to be bloodied in the competition after Henry Cullen and Reeve Evitts.
Davidson and Leach came into the side in place of keeper-batter Henry Cullen and pace bowler Ben Gibbon.
Libby put Glamorgan into bat on the same hybrid pitch as used for the splendid victory over Essex, and Leach made two early breakthroughs.
Tom Bevan had an escape on four when he was dropped at first slip off Dillon Pennington, but it was not a costly miss.
The opener added only six more before he played a shot off the back foot and was caught behind off Leach.
It became 16-2 when Glamorgan keeper batter, Chris Cooke, pushed forward and was bowled by a fine Leach delivery which nipped away.
Leach and Pennington posed plenty of problems with the new ball and conceded only 27 runs in the initial powerplay.
Kiran Carlson and Northeast rebuilt the Glamorgan innings and gradually upped the tempo, and the next ten overs yielded 71 runs.
But Ed Barnard produced an excellent spell from the New Road End, bowling his ten overs on the trot and finishing with 1-39.
He broke the third wicket stand of 95 in 15 overs when Carlson (41) nibbled at a delivery and gave Cox his second catch.
Davidson came into the attack for the first time at 119-3 and was unfortunate in his first over with Billy Root and Northeast both collecting boundaries from edges.
But then Root and Northeast scored freely and reached their half centuries off 66 and 68 balls, respectively.
They increased the tempo, and Northeast’s 172 not out was his and Glamorgan’s highest score in List A cricket.
Root ended unbeaten on 113, and the partnership of 245 was Glamorgan’s highest against any opposition for the fourth wicket in List A cricket.
When Worcestershire launched their reply, Ed Pollock played in a typically aggressive fashion, collecting five boundaries in three overs from Dan Douthwaite.
He made 27 off 26 deliveries but then aimed a legside blow at James Weighell, and top-edged a catch to third man.
Weighell struck again in his next over as Taylor Cornall, who hit a List A best 97 against Essex, was taken at mid off.
Libby and Gareth Roderick batted sensibly in consolidating Worcestershire’s position in adding 52 off eight overs.
But Prem Sisodiya accounted for Roderick (22), who was pouched at long on and then Barnard was caught and bowled low down by another spinner in Carlson at 116-4.
Libby continued to bat fluently, passing 300 for the tournament when on 26, and going on to reach an excellent half-century.
A single off Carlson took him to the fifty mark for the third time in the tournament, from just 48 balls and containing five boundaries.
The run rate reached ten an over, but Leach played positively from the start of his innings, striking Andrew Gorvin for a straight six.
He struck the ball in a superb fashion, similar to his match-winning knock against Kent chasing another big target in the Royal London Cup at New Road last summer.
Cox provided staunch support as the 50 stand came up in 37 deliveries, and then Leach completed a 31-ball half-century with his second six, a similar effort to his first one, this time off Sisodiya.
He had moved onto 63 from 36 balls when he tried to hit Joe Cooke over the top, and Northeast held onto a one-handed catch running back from extra cover.
The third half-century of the innings was completed by Cox from 58 balls with three fours before Tongue (23), and Finch (14) were caught in the deep.
Cox finished unbeaten, and his 78-ball knock included one six and seven fours.
