Second-placed Yorkshire cut the gap to leaders Durham as they claimed three bowling points on the first day against Sussex at Hove.
While Durham were frustrated by rain at Derby, Yorkshire reduced Sussex to 276-9 after winning the toss and bowling first on a green-tinged pitch which offered good pace and carry.
They would have been in an stronger position had it not been for an unbeaten 78 by Ben Brown, who celebrated his 50th first-class match with his first half-century since May.
Brown was badly dropped at second slip on 14 by Adam Lyth off Steve Patterson and Johnny Bairstow missed a stumping chance on 74. Brown added four more runs to finish undefeated on 78 before the umpires took the players off for bad light with 18 overs remaining.
Brown had earlier added 78 for the eighth wicket with Steve Magoffin after Yorkshire had dominated the first half of the day.
Some poor shot selection from the home side aided their attack. Apart from opener Chris Nash, who was caught behind off a superb delivery from Liam Plunkett, which bounced and found the edge, Sussex's top six got out to careless shots.
Luke Wells drove without getting to the pitch of the ball, Mike Yardy played on while attempting to play through the off side and skipper Ed Joyce played on to a ball from Ryan Sidebottom that swung back into the left-hander.
Rory Hamilton-Brown hit Kane Williamson for two sixes only to be bowled by the part-time off-spinner's arm ball later in the same over.
Matt Prior was nearly yorked by Plunkett first ball before he was bowled by Steve Patterson after lunch for 23 when only half-forward.
The comeback began when debutant Ashar Zaidi teamed-up with Brown to add 27 for the seventh wicket.
Zaidi, 32, is playing on a non-contract basis after impressing in the second XI, and in his first first-class match for four years he made 17 before Sidebottom trapped him lbw with a ball that might have been passing over the stumps.
It was Yorkshire's last success until after tea when Bairstow took an excellent catch diving in front of first slip as Magoffin chased a wide ball from Sidebottom.
Williamson picked up his second wicket when he yorked James Anyon, but Brown and Lewis Hatchett had added 22 for the last wicket when umpires Mark Benson and Steve O'Shaughnessy took the players off.