Derbyshire 551 for 8 dec (Madsen 176, Dal 146*) and 127 for 7 (Reece 42*, Brooks 5-46) lead Sussex 337 by 341 runs
Derbyshire's surprising decision not to enforce the follow-on against Sussex reduced their chances of winning a match they had dominated - and even gave their opponents an outside chance of pulling off an astonishing victory.
When Sussex were bowled out for 337 in this LV= Insurance County Championship match, losing their last five wickets for 38 runs and their last three in the space of four Hayden Kerr deliveries to concede a first innings advantage of 214, they looked down and out and not relishing the prospect of being put back in.
But Derbyshire decided to bat again and when they slumped to 54 for five, with Jack Brooks putting in a four-wicket burst, Sussex sensed the chance to pinch an outrageous win. Billy Godleman was well caught by Tom Alsop at first slip off Sean Hunt in the second over. That means the Derbyshire captain has 213 championship runs in 13 innings this season for an average of 16.38.
Then Brooks stepped up. He had Brooke Guest lbw for eight before dismissing the first-innings hero Wayne Madsen first ball, caught behind. In his next over Brooks dismissed Leus du Plooy, who mis-cued to midwicket, and in his next over Shan Masood dragged a wide ball onto his stumps.
Anuj Dal and Kerr fell near the close and Derbyshire closed on 127 for seven, a lead of 341. They are still favourites to win the game but Sussex can now see an escape route.
Sussex had started the third day on 142 for three, chasing a target of 402 to avoid the follow-on, with Mohammad Rizwan unbeaten on 54 and the in-form Oli Carter 14. Carter was dropped at first slip by Madsen off Sam Connors when he had made 26. Madsen should be forgiven, even by the most impatient of Derbyshire supporters. In all forms of cricket he has taken 313 catches for the county, placing 13th in Derbyshire's history - and seven of the 12 ahead of him were wicketkeepers.
Carter, who had scored a career-best 185 and 83 in the county's previous championship fixture against Glamorgan in Cardiff, went on to reach his half-century from 88 deliveries, with six fours. But then he was bowled going back when he might have been forward to one from the impressive Mark Watt, who was signed as a t20 player but who now appears to be the side's number one red ball spinner.
The spotlight on Rizwan was getting brighter with the fall of each wicket at the other end. And, making the most of the short boundary at the east side of the ground, he went on to reach his first championship century for Sussex from 172 balls, with 18 fours.
Sussex lost their fifth wicket at 242 when Danial Ibrahim, half forward to one that turned from Watt, was bowled for six. Delray Rawlins is a lavishly talented player who has not always shown shown enough discipline for the red-ball game. But he scored a half-century in Cardiff and here, against the spinners, he sensibly mixed aggression with patience. However, when Derbyshire took the new ball at 295 for five he was undone almost immediately, bowled through the gate by Dal as he played a loose drive. His 37 from 57 balls, with six fours and a six, was not what Sussex required.
Rizwan was lbw to Dal for a fine 130, with 22 fours, but the Sussex tail didn't wag, as Steve Finn fell second ball and Hunt to his first delivery.
