Derbyshire 138 (Wiese 4-18) and 437 (Reece 184, Godleman 106, Robinson 5-88) beat Sussex 231 (van Zyl 60, Reece 5-63) and 163 (Critchley 3-9, Dal 3-11, Hudson-Prentice 3-36) by 181 runs
Derbyshire ended a run of three Championship defeats with a 181-run victory over Sussex that put paid to the visitors' promotion hopes.
Ollie Robinson had given them hope with 5 for 88 and Reece Topley claimed 4 for 58 after Derbyshire lost their last eight wickets for 77 to be bowled out for 437, but that was soon snuffed out as the home side celebrated with more than 24 overs left in the day.
The damage to Sussex's prospects was inflicted on day two but at least the visitors responded with a vastly improved performance with the ball lead by Robinson. He ran in with intent to take the first five wickets before Topley polished off the tail to leave Sussex with a slim chance of pulling off the win they needed.
Their chase was made easier in theory by an injury to seamer Tony Palladino but Sussex could not put together a meaningful stand and came up well short.
Robinson showed what might have been if his side had bowled with discipline at the start of Derbyshire's second innings when he had Billy Godleman caught at second slip off the first ball of the day. Dal quickly followed, edging another that moved away late, and when Harvey Hosein fell across the crease and was lbw, the home side had lost three wickets in five overs.
Critchley and Matt McKiernan quickly followed and after Leus du Plooy and Hudson-Prentice took Derbyshire's lead towards 350, Topley completed a memorable return to championship cricket. He pinned du Plooy lbw and tempted Hudson-Prentice into a pull to deep midwicket before an inswinging yorker accounted for Dustin Melton.
Sussex knew time was not a factor and the wicket had flattened out but although several players got a start, none of them could play the substantial innings required.
Luke Wells was athletically caught at square leg by McKiernan and Will Beer played around his front pad to be lbw to Dal.
Phil Salt had flirted with danger numerous times before he steered Dal to fist slip and Delray Rawlins fell to a loose shot for the second time in the match in the penultimate over before tea.
Sussex's fate was settled when Hudson-Prentice had Stiaan Van Zyl and David Wieise caught behind off successive balls, leaving Ben Brown to watch helplessly as his side subsided meekly to the leg-spin of Critchley.