Worcestershire 185 (Kashif 52, Aitchison 4-40) and 108 for 5 (Aitchison 3-27) trail Derbyshire 130 (Dal 55, Pennington 4-36) and 343 (Dal 112*, McKiernan 71, Madsen 69) by 181 runs
Derbyshire's strong victory push was held up by the weather on day three of the LV=Insurance County Championship match with Worcestershire at New Road.
They set the home side a 289 target, after Anuj Dal completed a century, and had taken five top-order wickets before bad light and rain meant play was called off for the day at 5.10pm.
But the Peakites remain strong favourites to complete their third Championship win of the campaign tomorrow and keep alive their promotion hopes.
Ben Aitchison was again the chief thorn in Worcestershire's side with figures of 15-7-27-3 to take his wicket tally to seven in the game.
Derbyshire keeper Brooke Guest was again kept busy with two more dismissals to add to his six in the first innings.
But Worcestershire did not help their cause with several poor shots contributing to their downfall in a game where they held the initiative for most of the opening two days.
Only Jack Haynes and Gareth Roderick, during an unbroken stand of 36 spanning 18 overs, provided prolonged resistance.
Derbyshire resumed on 286 for six and the last four wickets fell for 57 runs in the space of 21.5 overs.
Dillon Pennington ended Dal's seventh wicket stand of 140 with Mattie McKiernan when the latter on 71 went for a pull and top edged a catch to third man.
Aitchison pushed forward to Joe Leach and was caught behind but then Dal, who resumed on 85, reached three figures with one of his few false strokes, an edge for four off Muhammad Hasnain.
It came off 189 balls with nine boundaries and he became the fourth Derbyshire player to score three hundreds this summer after Shan Masood, Wayne Madsen and Brooke Guest.
Sam Conners nicked Ed Barnard to second slip and George Scrimshaw picked out mid off against spinner Josh Baker to wrap up the innings.
Dal survived one chance on 110, dropped at backward point off Hasnain. Leach's three wickets means he needs just five more to reach the 400 mark in first class cricket.
Worcestershire openers Ed Pollock and Jake Libby batted aggressively in taking 31 off six overs before lunch but the game swung in the Peakites favour during the afternoon session.
For the second time in the game Pollock smashed Aitchison for six and was then dismissed to the very next delivery, this time falling to Hilton Cartwright at third slip.
Libby was caught down the leg side and Taylor Cornall's loose drive against Conners gave keeper Brooke Guest his eighth catch of the match.
There was no respite for the home side as Kashif Ali, fresh from signing a new two-year contract, chopped a Dal delivery onto his stumps.
Ed Barnard has so often been Worcestershire's savour this summer but he aimed a huge drive at Aitchison and Harry Came held onto the low chance at first slip.
Rain and bad light led to an early tea and an hour's delay and then Haynes and Roderick dug in to add an unbroken 36 before the weather closed in again.
