After being outplayed for the first half of the contest, when they sustained a first innings deficit of 134 runs, the home county were on 313 for six, a lead of 179, when bad light and rain brought about an early finish.
Samit Patel made 82 and Steven Mullaney scored 62 for the division two leaders, sharing in a stand of 137 for the third wicket.
Jeevan Mendis has picked up half of the wickets to fall, returning figures of three for 93 from his 24 overs.
Resuming from their overnight position of 67 for two, still 67 adrift, Mullaney and Patel were quickly into their stride, taking 14 from the first two overs.
Derbyshire rotated their bowling attack but on a placid wicket few opportunities were created as each batsman advanced to 50.
Mullaney, who scored 76 on the first day, reached the landmark from 98 balls, with seven fours. Patel’s first half century of the summer arrived from 104 deliveries, with eight fours.
In the final over of the morning Mullaney, on 58, had a life when he popped Mendis up to short leg but Alex Hughes couldn’t hold on.
Mendis got his man, early in the afternoon session, thanks to an excellent catch. The batsman had miscued a high pull and looked crestfallen as Tom Taylor ran back from midwicket and dived to take the ball as it dropped over his shoulder.
Patel was slightly unfortunate, when a delivery from Coner McKerr kept low and pinned him in front of all three stumps.
The fifth wicket pairing of Michael Lumb and Riki Wessels added 48 before Lumb popped Mendis up to short leg for 21.
The Sri Lankan leg spinner had a growing influence on proceedings, despite having long-hops pulled away for maximums by Wessels and Chris Read.
In fading light, a googly from Mendis deceived Wessels for 46 but Read was still there, also on 46, when bad light and drizzle ended play with 28 overs lost to the weather.
Without a championship victory since July 2015 Derbyshire’s mettle will be fully tested on the final day with all results now possible.