Openers Daryl Mitchell and Brett D'Oliveira both scored excellent centuries as Worcestershire dominated the third day of the Specsavers County Championship match with Derbyshire at the 3aaa County Ground.
Mitchell became the 25th player to score 10,000 first class runs for Worcestershire during a superb partnership of 243 in 54 overs with D'Oliveira.
It followed on from keeper Ben Cox claiming the 200th first class catch of his career after Derbyshire had been bowled out for 275 with maximum bowling points secured.
Mitchell's ton was the 25th of his career as he continued the form demonstrated in the Royal London One-Day Cup.
D'Oliveira completed his first three figure score since his 202 not out against Glamorgan at Cardiff last May.
He was finally dismissed for a magnificent 150 off 232 balls with 15 fours in the final over of the day.
Worcestershire reached 323-3 by the close – a lead of 48.
Mitchell and D'Oliveira have had to contended with some challenging conditions against the new ball in the opening part of the season but both showed their quality today.
Derbyshire resumed on 200-6 and Worcestershire skipper Joe Leach was again soon amongst the wickets.
Daryn Smit (33) was again given a searching examination before edging Leach to Mitchell who held onto a good low catch at second slip.
Leach picked up his fourth wicket as Jeevan Mendis (19) flicked him straight to Tom Fell at deep square leg.
The ninth wicket pair of Tom Taylor and Tony Palladino resisted for 20 overs in adding 45 before the former nicked an Ed Barnard delivery to Ben Cox – the 200th first class catch of his career.
Barnard wrapped up the innings in his next over as Palladino (32) was trapped lbw.
Leach finished with 4-50 from 23 overs and was well backed up by Barnard (2-33), Jack Shantry (2-49), Josh Tongue (1-62) and Nathan Lyon (1-73).
Mitchell and D'Oliveira showed positive intent from the start as Worcestershire tried to make up for the lost of 128.5 overs to the weather during the opening two days of the game.
D'Oliveira hit Taylor for four boundaries in one over although he had a let off on 42 when Ben Slater at square leg spilled a chance off Shiv Thakor.
Mitchell was first to his half century off 61 balls as the 100 came up in just 20 overs.
D'Oliveira went to the same mark from 79 deliveries and both batsmen were able to score freely.
Mitchell completed 10,000 runs for the county with a cover drive for three off Mendis and a back foot cover drive for two off Ben Cotton took him to three figures.
It came from 128 balls with one six and 11 fours.
An under edge for four off Thakor enabled D'Oliveira to complete his hundred from 160 deliveries – also with 11 fours.
The partnership was finally broken with 243 on the board in the 54th over as Mitchell was lbw to Thakor.
Fell (13) added 39 in 13 overs with D'Oliveirs before he chopped on against Mendis.
Leach promoted himself to number four and smashed two sixes in the space of three balls off Wayne Madsen.
D'Oliveira brought up his 150 off 230 balls with 15 fours but in the last over went for a big hit and top edged a return catch to Mendis who held onto the chance at short mid wicket.