Opener Luke Wells held Sussex's batting together with a patient 74 as his side were made to work hard for runs by a persistent Yorkshire attack on the opening day of the LV= County Championship Division One match at Arundel.
Sussex's decision to bat first looked an astute one at lunch when they were 108 for one but Yorkshire ripped through the heart of their batting in the afternoon when they took six wickets, including Wells, who was dismissed after nearly four hours in the last over before tea.
His dismissal left Sussex 188 for seven but James Tredwell, who was making his debut after joining on a month's loan from Kent, and Jon Lewis helped the tail wag to take their side to 300 for nine at stumps.
A pitch offering little pace or carry was hard work for the seamers but Yorkshire's quartet stuck to their task manfully, none more so than Tim Bresnan, who picked up three wickets - including the prized scalp of Ed Joyce for a duck - and beat the bat on several occasions.
However, too many Sussex batsmen got themselves out to balls they could have left alone, with Chris Nash first wasting a solid start when he chased Steve Patterson's loosener to depart for 28 before Wells and Rory Hamilton-Brown dug in either side of lunch in a stand of 60.
Hamilton-Brown greeted the arrival of off-spinner Azeem Rafiq, who was making his first championship appearance since last August with Adil Rashid on paternity leave, by lofting him for a six over long-on.
But Bresnan struck twice in five balls at the start of a productive afternoon for Yorkshire when Hamilton-Brown inside-edged behind two runs shy of his half-century and Joyce pushed fatally forward to a ball that swung late.
Patterson bowled a probing spell after lunch which was rewarded when Matt Machan was well held at backward point by Richard Pyrah, who had Ben Brown caught behind and then induced a faint edge from Wells with a ball which left him off the pitch.
It was a tame end to an impressive innings by the left-hander, who had faced 182 balls and hit 11 fours.
It left Sussex 188 for seven but Tredwell, Steve Magoffin and Lewis all chipped in with useful runs as their last three wickets added 112 either side of a short stoppage for bad light.
Tredwell made 45 before Bresnan pinned him lbw with second new ball but Lewis and last man Lewis Hatchett put on an unbroken stand of 52 for the last wicket, with Lewis reaching a 53-ball fifty in the final over of the day to take Sussex to an unexpected third batting point.
Tredwell, making his Sussex debut, felt that the 112 runs added so far for the last three wickets had left honours even.
"It's hard to say what a good score is until both sides have batted but we felt 300 for nine was a good effort considering the position we'd been in," he said.
"When the ball loses its hardness it can be tough to score because it's quite a slow pitch. I was glad to get some runs. When you join a team you want to make an impression quickly and hopefully I can do so with the ball tomorrow."
Yorkshire coach Jason Gillespie was frustrated by Sussex's tail-end resistance, saying: "I thought to get nine wickets on that surface was a good effort. Ideally we would have liked to have finished things off tonight but we need to get their last pair out early tomorrow and then getting batting."