With all eyes cast on James Tredwell the England off-spinner who, under ECB guidelines, had been controversially allowed to take his place in the Kent side at the mid-point of the match, it proved to be the home seam attack that duly wrapped up the club's fourth win of the campaign to maintain their title hunt against Yorkshire as well as the vanquished visitors.
In pursuit of an unlikely victory target of 404, Derbyshire started the day on 30 for one and with a determination, fired by the Tredwell debate, to bat it out. They scored 27 runs in the opening 70 minutes, dropping anchor through Usman Khawaja and the opener Paul Borrington.
The pair appeared content to pat it back all day as Charlie Shreck, Mark Davies and Tredwell, continued to bowl maidens. The plan worked until Kent turned to the hostile pace of the England Lions paceman Matt Coles.
With his second ball, a quick full-length delivery, Coles pinned Borrington leg-before and served up the same delivery to account for Wes Durston.
Having been dropped in the gully on nought, Durston had dug in with Khawaja after lunch until the introduction of Darren Stevens, the mild-mannered and seemingly innocuous Kent swing bowler, turned the course of events.
Stevens ended Khawaja's 206-minute stay with an in-ducker that won a leg–before-wicket appeal then, in the next over, Redfern pushed toward backward point and called for a single only to sell his partner, David Whiteley, down the river as Brendan Nash swooped to effect a stunning direct-hit run out.
Redfern, guilty and remorseful, soon hung a bat out against Stevens to be caught behind, leaving Kent the best part of three hours to whittle their way through the tailenders.
Stevens, with four for 37, ensured they did so with 43 minutes of the game remaining.
The victorious Kent captain, Rob Key, said: "With the pitch taking a bit of spin, I thought we might do it easier than we did, but Derbyshire really shut up shop and were hard work to prize out when the ball got soft.
"We had to force every dismissal, they were not caught covers, or caught on the hook, it was just bloody hard work.
"There was a lot of rough and a lot of risk had they have tried to hit Treddy they would have been risking their wickets. As it was they dig a bunker against him and hung in there. As a result, he bowled a lot of overs yet didn't get a wicket."