Sussex all-rounder Chris Jordan became the first man to reach 50 LV= County Championship wickets for the season on the second day of the Division One game against Derbyshire at the BrightonandHoveJobs.com County Ground.
Jordan reached the landmark when he had Tim Groenewald well caught by Michael Yardy at second slip to give him his third scalp of the day.
Derbyshire, still looking for their first win of the season, were made to battle hard for runs, even though the ball did not swing as generously as it did on the opening day. They were bowled out for 274, conceding a first-innings lead of 40.
At stumps, Sussex had extended their lead to 51 on 11 for one, with opener Chris Nash bowled by Groenewald just before the close.
Captain Wayne Madsen was the only specialist batsman to offer strong resistance, batting four minutes short of four hours to compile 97 but there was valuable support lower down the order from Peter Burgoyne, who scored his maiden championship fifty in only his second match.
Sussex, looking for their fifth win of the season to maintain their challenge for the championship title, took their first wicket of the morning when Jordan had Chesney Hughes caught behind for 16.
Three overs later, Steve Magoffin ousted Ben Slater in identical fashion for 16 and Derbyshire were 40 for two.
Luke Wright, operating off a shortened run, appeared to be the least threatening of the Sussex bowlers but put his side well on top with two quick wickets.
First, he had Shivnarine Chanderpaul brilliantly caught by Jordan, low to his left at first slip, and then dismissed Richard Johnson, who played a weak shot to short cover. When Jordan had Alex Hughes - making his first-class debut - taken at short-leg, Derbyshire were in trouble at 103 for five.
But Madsen led the recovery, first adding 36 with Tom Poynton and then 78 with Burgoyne, who finished unbeaten on 62 from 105 balls, with eight fours and a six.
Madsen was seventh out, lbw to Monty Panesar as he played to leg and, after Jordan got rid of Groenewald and Magoffin dismissed Matthew Higginbotham, Ed Joyce wrapped up the innings by running out Mark Footitt.