Zak Chappell bolstered Derbyshire's chances of claiming a long-awaited County Championship win at Derby by dismantling Glamorgan on the first day of their Division Two clash.
Chappell delivered a career-best performance for Derbyshire, taking 6 for 47 as Glamorgan was dismissed for 168, with Timm van der Gugten top-scoring with an unbeaten 46.
Glamorgan found themselves in deep trouble at 32 for 6, but a brief recovery led by Dan Douthwaite and van der Gugten provided some resistance. By the close of play, Derbyshire had reached 119 for 2, with Harry Came unbeaten on 58, putting them in a strong position to push for their first Championship win at the County Ground since defeating Sussex in August 2019.
On a morning that felt more like October, Derbyshire's decision to bowl first on a grassy wicket paid off immediately, with three wickets falling in the opening five overs.
In challenging, windy conditions, Glamorgan's top order struggled against Chappell's pinpoint accuracy and Luis Reece's swing, slumping to 9 for 3. Ben Kellaway, promoted to opener, was dismissed for a duck, edging a late-moving delivery from Chappell in his third red-ball innings. The more experienced Glamorgan batsmen fared no better, with Billy Root bowled by a low-keeping delivery from Reece, and Sam Northeast caught at second slip off Chappell.
Kiran Carlson misjudged a delivery from Chappell that seemed to be missing the stumps, and Reece's late swing had Colin Ingram caught behind. When Chris Cooke edged one of Chappell's few loose deliveries down the leg side, Glamorgan was in tatters, only somewhat relieved by the rain that forced an early lunch.
Chappell, who surpassed 50 wickets in all formats this season, initially boasted figures of 4 for 9 from 6.4 overs, but Douthwaite dented them slightly by hitting him for three boundaries in an over after the break.
Van der Gugten and Douthwaite put together a 55-run partnership from 97 balls, playing with relative ease until Pat Brown dismissed Douthwaite with a delivery that nipped away late to remove the off stump.
Chappell claimed his fifth wicket when Mason Crane edged a ball to give Brooke Guest his fourth catch, and although debutant Fraser Sheat looked solid, he eventually top-edged a pull to midwicket.
Ned Leonard, playing his first match on loan from Somerset, partnered with van der Gugten to push Glamorgan past 150, even hitting Jack Morley's second ball for six before being caught at long-on attempting the same shot.
Van der Gugten bowled with the same discipline as Chappell, but Sheat and Leonard couldn't maintain similar pressure. Reece and Came, who had shared a record partnership against Glamorgan last season, managed just 21 this time before Reece was bowled by a full-length delivery from van der Gugten.
Guest fell after playing a loose shot, clipping Leonard to midwicket with the score at 41, and Came had a lucky escape on 28 when Ingram dropped an edge at first slip off Leonard.
Taking full advantage, Came punished any loose deliveries, reaching a fifty off 84 balls, including 10 fours. He and Wayne Madsen, who raced to an unbeaten 41, added 78 runs before bad light ended play.