Joe Leach made a quickfire breakthrough but Worcestershire were then held up by the Derbyshire third wicket pair of Billy Godleman and Wayne Madsen on day two of the Specsavers County Championship clash at the 3aaa County Ground.
Leach sent back Wayne Rutherford and Chesney Hughes in the space of four balls after Worcestershire skipper Daryl Mitchell opted to bowl when play was finally able to get underway after a first day wash-out.
But Godleman and Madsen put together a record third wicket stand of 251 for Derbyshire in matches against Worcestershire as both batsmen reached the century mark.
By the close Derbyshire had reached 319-3 off 96 overs with Godleman unbeaten on 157.
Leach shared the new ball with Matt Henry who came into the side in place of Charlie Morris in the only change from the side beaten by Gloucestershire in the last Championship match three weeks ago.
The all-rounder made the first breakthrough in his second over when Rutherford (5) shouldered arms and was bowled.
Leach struck again when Chesney Hughes was trapped lbw without troubling the scorers to leave Derbyshire on 13-2.
Runs were hard to come by in the morning session and Derbyshire reached 66-2 off 31 overs by the interval.
But Godleman and Madsen blossomed during the afternoon session when 148 runs were added off 33 overs.
Godleman survived a chance on 62 when Ross Whiteley put down the opportunity at gulley off Henry.
He went to his century off 177 balls with a six over long on off Brett D'Oliveira and also struck 14 fours.
Mitchell rotated his bowlers in an effort to make a breakthrough as the 200 partnership came up in 58.4 overs.
But Madsen brought up his ton off 213 balls with 12 boundaries out of 232-2 in the 72nd over.
It was Shantry who broke the stand when Madsen on 109 edged through to keeper Ben Cox with the total 264-3 in the 79th over.
The scoring rate dropped with the taking of the second new ball at 269-3 off 80 overs.
But Godleman went to his 150 and by the close had faced 259 balls and struck 21 fours and a six.
