Sussex were 100-3 at the close of play on day two after Durham posted a first innings total of 231.
Dale Benkenstein and Paul Collingwood returned to the crease on day two but only five runs were added to the total before the latter was caught behind off Steve Magoffin for 9.
Phil Mustard and Benkenstein battled hard through the remainder of the morning session as the Sussex attack bowled tightly. As the sunny conditions changed, with the temperature dropping and cloud descending the 60 run partnership was brought to an end by Monty Panesar who has Mustard (27) caught in the slips by Chris Nash just before the lunch break.
Durham were 170-7 after they lost Benkenstein, who was caught by Wernars off Magoffin for 43, early on in the afternoon session and were quickly eight down with Callum Thorp caught by Goodwin off the bowling of Luke Wright for 4, four overs later.
A 55 run partnership between Mitchell Claydon and Scott Borthwick, whose own fifty came from 67 deliveries and included eight boundaries – before he was trapped lbw by Nash -, helped Durham secure their only batting bonus point.
Durham posted a first innings total of 231 as Claydon was caught by Wells off Nash for 15, leaving Chris Rushworth unbeaten on one.
Rushworth was first to strike in the Sussex innings, trapping Nash lbw on 4 in the third over. Tight bowling from the Durham attack, including four consecutive maidens from Rushworth, saw the hosts tied down pretty much at both ends and unable to score quickly.
Sussex were 42-2 in the 20th over when Thorp claimed the second scalp, that of Joe Gatting, who was trapped lbw on 11.
Dangerman Luke Wells (41) was bowled by Thorp four overs later bringing Michael Yardy to the crease to join Murray Goodwin. At the close of play on the third day Sussex were 100-3.
Durhamccc.co.uk spoke to Scott Borthwick at the end of the day, who said, “It was my first fifty of the season and it was nice to spend some time in the middle and score some runs. When Benks and Thorpy got out me and Mitch decided that we needed to bat positively and that’s what we did.
“I thought once I got in it became a lot easier, when I first got in it was a bit two-paced and was nipping around a bit. It’s a shame that we didn’t get to 250 for that extra batting point but I still think 230 is a good score. If our seamers can stay patient and get the ball in the right areas we’re definitely in with a chance. There’s still a bit in the pitch so hopefully we can take early wickets tomorrow.”