At stumps, the home side closed on 228 for seven in their second innings, an overall lead of 294, with Samit Patel undefeated on 88, his highest score of the season.
Patel, who has scored his runs from 129 balls, with 11 fours and a six, shared in an unbroken eighth wicket stand 120 with Luke Wood, who was unbeaten on 52 at the close.
Steve Magoffin was again the pick of the visitors’ attack, ending the day with four for 48, to give him 10 wickets in the match.
Earlier in the day Sussex were dismissed for 189, with 24-year old Jake Ball taking career best figures of six for 49 for Notts.
Ball was soon on course for his first five-wicket haul by removing Chris Nash, Luke Wright and Ben Brown in his opening burst of the day, adding to his lone success on the first evening.
Craig Cachopa and Chris Jordan held up the hosts with a seventh wicket partnership worth 69, although both players were spilled in the slip cordon.
Wood, Nottinghamshire’s first day centurion, broke the stand by bowling Jordan for 39 but Cachopa advanced to his 50, made from 80 balls with eight fours and a six.
He only added four more runs before being bowled by Ball, who followed up by getting Matt Hobden lbw to finish the innings.
Nottinghamshire’s second innings was soon in disarray as Magoffin and Ollie Robinson shared the opening four wickets to fall.
Brendan Taylor was bowled for seven by the Australian, who then had Alex Hales caught behind for five.
Steven Mullaney edged Robinson to first slip, where Jordan took a sharp catch with his customary ease, then the same bowler dismissed James Taylor lbw.
Riki Wessels made 26 before hoisting Chris Jordan down to third man where Luke Wright took a well-judged catch. Magoffin made it ten wickets in the match by removing Greg Smith and Will Gidman in his first over after tea.
Samit Patel reached his third Championship 50 of the summer from 65 balls, with eight fours and received solid support from Wood.
For the second time in the match the young left-hander played an impressive hand, although he received a huge slice of fortune on 35 when he was bowled by a Jordan no ball.
Sussex were made to pay for that reprieve as Wood proceeded to his 50, getting there from 81 balls, just before the close.