Sussex were 112-5 at the close of play on day two at Emirates Durham after they dismissed the hosts for 227
An 83 run partnership from Phil Mustard (45) and Scott Borthwick (35) saw Durham reach Sussex’s total and go on to secure a marginal lead before the final four wickets fell for just 25 runs.
Kirk Wernars picked up two wickets with one apiece for Chris Nash and Monty Panesar.
Taking to the field in their second innings Sussex reduced the deficit of 16 pretty swiftly losing Nash in the process who was out lbw to Chris Rushworth off the ninth delivery.
Luke Wells and Mike Yardy added 40 before the latter was out lbw to Thorp for 29 in the 14th over. Ben Stokes and Phil Mustard combined twice in five overs to dismiss Joe Gatting and Matt Machan (6) reducing Sussex to 68-4.
The following over saw Callum Thorp claim his second scalp, that of Wernars, who was trapped lbw for just 1.
Bad light saw three overs lost in the final session and by the close of play Sussex were leading by 96 with 112-5, Wells 51* and Brown 12*.