Derbyshire captain Wayne Madsen batted for three and a half hours for a stoic 59 to help his side reach 231 for seven, securing a precious 161-run lead on the penultimate day of their LV= County Championship Division One clash with Surrey.
With only two batsmen reaching 50 in the match, contributions from Paul Borrington and Richard Johnson, with 38 and 27 respectively, plus Tom Poynton, who will resume unbeaten on 29, could yet heavily influence events on the final day at the Kia Oval.
Derbyshire resumed on their overnight score of 13 without loss - a deficit of 57 - and suffered an early blow when Tim Linley removed Ben Slater in the seventh over of the day to a lofted catch at point by Zafar Ansari.
Madsen, having recovered from being struck on the helmet when a delivery from Linley reared up alarmingly, shared a watchful second-wicket stand of 51 in 26 overs with Borrington.
Borrington hit just four boundaries in nearly two and a half hours at the crease, one of which sailed through cover off George Edwards.
Madsen drove Ansari through extra-cover for four to bring the sides level, but Borrington's vigil ended when he lost his off stump, offering no shot to the fifth ball after lunch.
In the 11th over after the break Shivnarine Chanderpaul doubled the number of runs made since the interval by pulling Linley for four.
Madsen then struck three boundaries in over from Edwards, but was fortunate to survive a sharp chance to short-leg, off Ansari, on 47.
Ten overs later, Madsen moved to his fifty, which came off 137 balls and included five fours, though not before Chanderpaul had departed lbw to Gareth Batty for 14.
Madsen celebrated his half-century by cover-driving Batty for four, but the re-introduction of Chris Tremlett immediately after tea sparked the loss of three wickets in four overs.
Madsen was lbw for 59 to a ball that kept low, Johnson played around a leg-stump delivery from Ansari and Tremlett struck again when Alex Hughes was beaten for pace to depart leg-before.
Spurning the opportunity to take the second new ball when it became available, Batty, Surrey's skipper, had Peter Burgoyne caught low down at slip.
But then Poynton and David Wainwright gave Derbyshire renewed hope of setting their hosts a target in the region of 200 by adding 48 in 18 overs for the eighth wicket.
Poynton lifted Batty over wide mid-on for four and, after the new ball had been removed from its wrapper, edged Linley to third man before driving him past mid-off for four.
At stumps, Poynton had faced 87 deliveries for his 29, while Wainwright, who hit just one boundary, had an undefeated 22 off 51 balls to his name.