Five-star duo put Kent in command
Doug Bollinger and Darren Stevens took five wickets apiece as Derbyshire were skittled for just 118 after their clash with Kent got under way.
Following a washed out first day on Sunday and further wet weather on Monday morning, play began just after 2.30pm - but Derbyshire must have soon been wishing the delay had lasted even longer.
The hosts, inserted by their opponents, were quickly in trouble as they slipped to 24 for three, which, after another rain interruption, then became 57 for five.
And they subsequently lost their last five wickets for just 15 runs, with Australian paceman Bollinger and veteran all-rounder Stevens finishing with figures of five for 29 and five for 24 respectively.
Kent then closed a good day for them on 10 without loss, Sam Northeast (nine) and captain Rob Key (one) the men at the crease.
The home side's troubles started when they lost their first wicket with just four runs on the board, Stephen Moore trapped lbw by Bollinger.
Paul Borrington was next to depart, caught by Adam Riley off the bowling of Stevens, leaving his team on 24 for two and skipper Wayne Madsen swiftly followed, becoming Bollinger's second victim as Brendan Nash made the catch at point.
After a short shower halted play, the wickets continued to fall, the usually-dependable Shivnarine Chanderpaul making just five before falling lbw to Stevens with Derbyshire on 38, and Scott Elstone then fell to the same bowler in the same fashion.
There was something of a rally, with a stand of 46 being put together for the sixth wicket through Alex Hughes - who ended up as top-scorer with 36 not out - and Gareth Cross.
But then Bollinger intervened with three quick wickets as Cross, David Wainwright and Tony Palladino were caught, Stevens snaring the first and wicketkeeper Sam Billings then holding on to two chances.
Only three more runs were added before Tim Groenewald was ousted by a stunning one-handed catch from Key off Stevens.
And after the addition of five more, Stevens wrapped things up by bowling Mark Footitt, before Northeast and Key got Kent's reply started without any setbacks.