Centurions Jake Libby and Brett D’Oliveira rewrote the record books as Worcestershire secured maximum batting points on day two of the Bob Willis Trophy encounter with Glamorgan at Blackfinch New Road.
The duo set a new partnership record for Worcestershire for any wicket against their Welsh opponents, surpassing the 287 by Graeme Hick and Tim Curtis for the second wicket at Neath 34 years ago.
Libby also achieved his career-best score, beating his 144 for Nottinghamshire versus Durham four years ago, and the fourth wicket stand was worth 318 in 81 overs when he was dismissed for a superb 184.
D’Oliveira went onto make a magnificent 174 as Worcestershire reached 455-8 in their permitted 120 overs and ensured they accumulated five batting points.
It followed on from their equally impressive 428-5 in the first innings against Gloucestershire in the opening Bob Willis Trophy encounter which ended in an eight-wicket success.
Libby has now scored 286 runs in his first three knocks for Worcestershire and D’Oliveira 265 runs in two innings this summer.
When Glamorgan launched their reply, Ed Barnard removed Glamorgan openers Nick Selman and Charlie Hemphrey inside his first three overs to leave the visitors on 44-2.
The Worcestershire bowlers stuck to their task and on another day may have claimed a couple more successes with the new ball.
Dillon Pennington also bowled sharply without any tangible reward in his first appearance of the campaign.
But Kiran Carlson (76 not out) and Billy Root (53 not out) dug in after tea to steer Glamorgan to 181-2 off 61 overs by the close.
Worcestershire Assistant Coach-Bowling Coach, Alan Richardson, said: “The wicket has been a really true surface, it’s gone through nicely and it’s carried, but when the newness of the ball goes, it can be tough work for the bowlers.
“The key was to try and make inroads. I thought we bowled brilliantly at the start and we stuck at it the whole way through and probably didn’t quite get our rewards right at the beginning, so that’s frustrating.
“Dillon was really powerful at the crease and is a real athlete and a real asset to us, and it was nice for him to get on the park and get some overs under his belt and I thought he was a threat for us.
“However, the two guys from Glamorgan (Carlson and Root) have batted well and applied themselves just like Jake and Brett did for us.
“We are going to have to stick at it now and hope we can make a breakthrough tomorrow morning.”
Richardson was delighted to see Barnard pick up his first wickets of the campaign.
He said: “Barny made it clear that he had a ‘fresh air’ game last week when he didn’t get any wickets or didn’t get the chance to bat.
“It was nice for him. I think he has bowled well. He was a vital part of the bowling group at Bristol even though he didn’t get any wickets. He helped other guys to get their’s, and it was nice for him to get amongst the wickets today.”
Worcestershire resumed on 309-3 from 91 overs, and Libby and D’Oliveira were initially watchful against the second new ball attack of Michael Hogan and Timm van der Gugten.
But the scoring rate gradually picked up, and Libby went past his previous highest score when he clipped van der Gugten through mid-wicket for two.
The former Nottinghamshire batsmen then reached 150 with a cover drive for three off Hogan.
The new partnership record was achieved with a chop for two off-spinner Kieran Bull by D’Oliveira who then reached his own 150 with a single off the same bowler.
Both batsmen looked in complete command until Libby came down the wicket to Bull and was stumped by Cooke at 388-4.
The 27-year-old batted for 429 minutes, faced 319 balls and struck one six and 18 fours.
Worcestershire earned their fifth batting point with seven balls to spare of the 110 overs before late wickets were sacrificed in the late chase for runs.
Riki Wessels (4) was caught and bowled by Graham Wagg and D’Oliveira’s splendid knock came to an end when he tried to steer Wagg down to third man and departed to an excellent low catch by keeper Chris Cooke.
Wagg claimed a third scalp as Ed Barnard (7) holed out to Hogan at long off.
Worcestershire Club captain Joe Leach (17) swatted Bull over the mid-wicket boundary for six to bring up the 450 before he was caught in the deep attempting a similar hit to the next delivery.
When Glamorgan launched their reply, Selman and Hemphrey advanced the total to 39 but both quickly departed after Barnard’s introduction into the attack.
The last ball of his first over accounted for Selman (22) who nicked an excellent delivery which moved away through to keeper Ben Cox.
It became 44-2 when Hemphrey (16) was leg before to the England Lions all-rounder in his third over.
Carlson and Root both completed half-centuries off 95 and 109 balls respectively during the final session.