Joe Clarke achieved his career best score and Joe Leach a first century for three years as Worcestershire's batsmen dominated a rain-truncated second day against Derbyshire at New Road.
Clarke, who was unbeaten on 117 overnight, went on to make 194 as he surpassed his previous best tally of 135 against Gloucestershire at Bristol in his first innings of the summer. Leach made an unbeaten 107 before the declaration came at 475-7 in mid afternoon.
But a mixture of bad light and then persistent rain meant Derbyshire faced only 2.3 overs before play was abandoned for the day.
Worcestershire had to battle hard on a sluggish pitch to reach 255-6 from 92 overs on the opening day. But it was a different scenario on Wednesday as they plundered 220 from 45 overs today at nearly five runs an over.
Clarke and Leach put on 157 in 32 overs – a Worcestershire record for the seventh wicket in matches against Derbyshire. England Lions player Clarke was eventually dismissed in the final over before lunch, caught at deep mid wicket off Wayne Madsen aiming for the big hit which would have taken him to his double hundred.
Clarke struck one six and 25 fours in his 328-ball knock and his first full season of senior cricket has brought him five Championship hundreds and a 98. Leach was then given good support in an unbroken eighth wicket stand of 72 in 14 overs with Ed Barnard (32 not out).
The 25-year-old Leach went to his hundred off 138 balls with 12 boundaries via a four through mid wicket off Tony Palladino shortly before the declaration. It was the first time he had reached three figures since his career best 114 – and maiden ton – versus Gloucestershire at Cheltenham in 2013.
Leach was batting in the top six on that occasion but since then his bowling skills have improved considerably and he is now a front-line part of the attack. In addition to scoring nearly 600 runs batting at number eight, he is Worcestershire's leading wicket-taker in the Championship this summer with 58 victims.
Miguel Cummins took the new ball for Worcestershire fresh from his 12 wickets in the win over Sussex at Hove. He should have collected another scalp with his third delivery but Ben Slater on two survived a chance off a skier at fine leg.
Only 15 balls were possible before the players left the field and then a heavy post tea downpour ended hopes of a return to action.
Worcestershire centurion Joe Leach said: "It has been a long time coming. I've got a few scores, 80s and 90s, but it is nice to get over the line and Jack Shantry might just have to be a little bit quieter now because he was 2-1 up in terms of hundreds scored.
"We are 2-2 now thankfully because I can't have him beating me in the century stakes!
"The rain is a shame because we set the game up to have a good go at them this afternoon but it wasn't to be. We will go again tomorrow morning and we've got two days to bowl them out twice."