Sussex 82 for 1 (Haines 54) trail Durham 223 (Trevaskis 88, Clark 3-21, Beard 3-51) by 141 runs
Sussex enjoyed their best day of the season in the LV= County Championship, dismissing Durham for 223 before skipper Tom Haines made his third half-century of the season as they reached 82 for one on the first day at Hove.
Durham's total represented something of a fightback after they had been 75 for six with Liam Trevaskis supervising their recovery with a career-best 88.
Aaron Beard, on his Sussex debut after signing for a month from Essex, and Tom Clark both took three wickets but Durham's total looked some way short of par.
And Haines and Orr put conditions in perspective in a first-wicket stand of 68. Haines hit ten fours, including three in one over off Matt Salisbury, and it was a surprise when Matthew Potts bowled him off a very thin inside edge for 54.
The pitch looked good for batting but Durham, who won the toss, soon lost opener Alex Lees although it was a misjudgement by the England opener, who drove loosely at Henry Crocombe and was caught behind in the sixth over.
There were few alarms for Sean Dickson and South African Keegan Petersen who took the total to 61 when Clark picked up his first wicket. Again, it was a misjudgement by the batter as Petersen drove off the back foot straight to backward point.
Suddenly Durham's top order had been blown away in a mad half-hour as five wickets tumbled for 15 runs in 7.1 overs. Clark picked up Dickson playing across a straight one and in the next over Beard struck in his ninth over as David Bedingham got a thin edge as he pushed forward.
Skipper Haines replaced Beard and had immediate success when skipper Scott Borthwick was well caught in the gully by Orr. In the next over Clark had his third wicket with Ned Eckersley also leg before playing across the line.
Durham were 79 for 6 at lunch but Trevaskis and Ben Raine regrouped in the afternoon. There was an extraordinary moment when Crocombe pitched the ball on the second bounce on an adjoining pitch and Trevaskis stepped several yards out of his crease to swipe it down to fine leg.
Their seventh-wicket stand had been worth 53 in 17 overs when Beard struck in the third over of his new spell as Raine fell leg before to a delivery slanted across him.
Leg-spinner Mason Crane has also joined Sussex on a month's loan from Hampshire but Trevaskis greeted his arrival into the attack by hitting successive boundaries to bring up his fifty and he progressed to a fine 88 in a stand of 87 in 26 overs with Matty Pott.
But Crane returned after tea to have Trevaskis superbly caught at short fine-leg by the diving Orr and Potts held off a top-edged slog sweep in successive overs. Beard took a return catch off Matt Salisbury to finish with 3 for 51 while Clark was the pick of the attack with 3 for 21 from 17 overs.
Durham's attack leader Chris Rushworth needed a concussion check after he was struck on the back of the helmet by Clark's bouncer and Rushworth had little luck when he took the new ball as Haines and Orr ensured it was Sussex's day.
