Jordan Thompson claimed three wickets for Yorkshire, but the opening day at Emerald Headingley belonged to Sussex captain Ben Brown, whose unbeaten 126 underpinned a fightback from early strife.
Wicketkeeper Brown proved a thorn in White Rose sides once more with a third LV= Insurance County Championship career century in 13 innings against them.
He shared 107 for the fifth wicket either side of tea with Aaron Thomason (40) to recover the visitors from 68-4 to a much more healthy 267-5 from 96 overs at close.
Thompson claimed two of the first four wickets after Steve Patterson had won his seventh toss in eight games this summer, and he later finished with 3-42 from 19 overs.
A crowd of 2,056 watched Yorkshire’s first team for the first time since September 2019.
The White Rose are aiming to bounce back from last week’s Roses defeat and will remain confident of doing so despite inexperienced Sussex’s industrious recovery on what looks to be a good batting pitch.
They are missing the likes of Jofra Archer, Ollie Robinson, George Garton and are handing a debut to 16-year-old all-rounder Dan Ibrahim, who ended the day unbeaten on 37.
Yorkshire shaded the opening session, with David Willey, Thompson and Harry Brook all striking to leave the score at 63-3 after 31 overs.
Willey made the breakthrough when he had Tom Haines caught at third slip in the fourth over – 8-1.
Thompson and then Brook struck in their first overs.
Thompson had Stiaan van Zyl caught behind – 25-2 after 11 – before Brook had Ali Orr caught at long-leg for 15 by Duanne Olivier as the score fell to 38-3 in the 23rd.
Brook’s wicket was with his first ball, and Olivier was briefly on the field as a substitute for Willey.
Willey replaced Olivier in the team as one of three changes from the last round Roses defeat at Old Trafford. Gary Ballance and Dawid Malan are both in for Will Fraine and George Hill.
Explaining the decision to bowl, the morning session was played under a grey sky with the Headingley floodlights on, much the same until the early stages of the afternoon.
And Yorkshire struck again two overs after lunch when Thompson had Australian overseas left-hander Travis Head caught behind for 14 against his former county as Sussex slipped to 68-4 in the 33rd.
That was the third wicket to fall in the opening over of a bowler’s spell, but things were about to get more challenging for the White Rose.
The sun came out and Brown and Thomason turned the tide for a visiting side fielding two first-class debutants in 20-year-old left-handed opener Orr and 16-year-old Ibrahim.
Ibrahim, at 16 years and 298 days, is the second youngest player to represent Sussex at this level. Last summer, left-arm spinner James Coles debuted for the Hove county aged 16 years and 157 days.
While Thomason dropped anchor – his 40 took 181 balls – Brown was much more punchy as he enhanced an enviable career record against Yorkshire.
Brown drove well against seam and spin and reached 50 off 60 balls, notching 8,000 first-class career runs along the way.
Sussex scored 100 for the loss of only Head in 33 afternoon overs.
Brown and Thomason brought up their century partnership shortly after tea – 168-4 in the 69th over – only for Thompson to get the latter caught at mid-wicket seven runs later.
Ibrahim got off the mark first ball with a clipped two and looked composed as he navigated the new ball late in the day.
Brown reached his 19th career century in all, and his first in two years, off 149 balls as Sussex moved to 208-5 in the 85th over.
The pair will resume their unbroken sixth-wicket stand of 92 at the start of day two. Brown hit 18 fours in 174 balls.