Harvey Hosein scored his maiden County Championship century but Derbyshire were forced to follow on after another impressive performance with the ball by Worcestershire paceman, Joe Leach, at New Road.
Wicket-keeper Hosein registered his fourth successive fifty score and reached three figures off 240 balls with his 11th boundary – through mid-wicket off Ed Barnard.
It was a perfect reminder of his potential in the week that Derbyshire signed Gary Wilson from Surrey on a three-year contract.
But Leach followed up yesterday's century with his fifth five wicket haul of the campaign as Derbyshire were bowled out for 248.
Only Hosein and Championship debutant Greg Cork (49) provided prolonged resistance as Derbyshire followed on – 227 in arrears.
Then Leach struck an early blow in Derbyshire's second innings to remove Ben Slater as the visitors closed on 15 for one.
The 25-year-old all-rounder is having a season to remember and he has now taken 64 Championship wickets to surpass last year's previous best tally of 59 in addition to scoring more than 600 runs in the competition.
Derbyshire resumed on 15-0 and were immediately on the back foot after Leach removed Billy Godleman and Tom Wood in the space of five balls.
He had Godleman (11) caught behind – an excellent take by Ben Cox diving away to his left - and trapped Wood lbw for a duck in the same over.
Miguel Cummins worked up a good head of pace and had Wayne Madsen lbw before Charlie Morris made a double breakthrough.
Slater (25) edged through to Tom Kohler-Cadmore at first slip and the same combination accounted for Alex Hughes. It became 103 for six shortly after lunch when Tom Milnes was caught behind.
But Cork, son of former England all-rounder Dominic Cork, joined Hosein to frustrate the Worcestershire attack for 33 overs during a seventh wicket stand of 96.
Hosein came to immediate prominence when he made his first-class debut against Surrey at The Oval in 2014.
He claimed 11 catches to break the Derbyshire record for the most dismissals in a match by a wicketkeeper. It also equaled the world record for dismissals by a wicketkeeper on debut.
But here the 20-year-old showed more of his potential with the bat after scores of 52 and 83 both not out against Gloucestershire with 58 versus Leicestershire in his previous three knocks.
Cork was denied his maiden 50 when he pulled Leach into the hands of Joe Clarke in front of square.
Hosein's march towards three figures was threatened when Ed Barnard trapped Tony Palladino lbw and bowled Will Davis with successive deliveries.
He then survived a run out scare on 97 before going to his hundred and reached 108 before Leach claimed his fifth wicket.
Slater departed for the second time in the day when he clipped Leach to Tom Fell at mid-wicket.