Three-wicket haul for Matt Critchley as Derbyshire dominate Worcestershire
The 24-year-old followed his century on day one by snaring three wickets with his leg spin to leave Worcestershire on 243 for 7 at the close, still 147 runs behind.
Derbyshire fast bowler Sam Conners said: "We always knew the pitch would have a bit in it early on and I thought we used the new ball really well.
"It's important that we come back and not think the wickets are just going to come but make sure we bowl like we did today and are right on it from ball one and hopefully get them out cheaply."
On Matt Critchley he said: "I know just how hard he's worked this winter on his bowling, making sure his variations are all up to scratch and it's showing in how he's bowling. You give him the ball in any scenario and he'll probably pick you up a couple of wickets, he's a great asset for us."
Tom Fell scored 69 and Riki Wessels 60 after Derbyshire had been bowled out for 390 with Ed Barnard taking 4 for 67.
Derbyshire went into day two needing 40 runs to secure maximum batting points but Barnard cleaned up the tail to leave Harvey Hosein stranded on 83.
Worcestershire’s chances of a third bowling point appeared to have vanished when Wessels dropped Ben Aitchison at first slip off Alzarri Joseph but three balls into the 110th over, Aitchison was caught behind off a short delivery from Barnard.
Sam Conners was bowled in Barnard’s next over but Worcestershire’s reply began badly when Jake Libby was out to the second ball of the innings.
He was beaten by a full length ball from Connors and Derbyshire struck another big blow just before lunch when Daryl Mitchell was beaten by an inswinger from Fynn Hudson-Prentice which sent his middle stump cartwheeling.
Fell was looking secure but Critchley deceived Gareth Roderick in the flight and plunged to his left to take a smart return catch.
Brett D’Oliveira and Fell were steering Worcestershire into calmer waters but two wickets in the space of three overs plunged them back into trouble.
Fell clipped Michael Cohen off his legs for his 10th four to reach fifty off 141 balls but Connors had him lbw playing across the line and D’Oliveira went on the stroke of tea when he edged Critchley low to slip.
At 135 for 5, the follow-on target of 241 looked a long way off but Wessels played fluently, reaching his second fifty of the season from 77 balls and adding 82 in 27 overs with Ben Cox before Critchley struck again.
Wessels was beaten by a googly which ripped through his defences and Critchley put down a return chance before Barnard had scored but Cox was bowled trying to leave Luis Reece when Derbyshire claimed the new ball.