A fighting century from Sussex captain Ed Joyce frustrated LV= County Championship Division One leaders Yorkshire in front of a 4,624 crowd on the first day of the match at the Scarborough Cricket Festival.
Joyce fell to the last ball of the day for 130 from 240 deliveries with 15 fours, leaving Sussex on 315 for eight, and Yorkshire still have a lot of work to do if they are to extend their five-point lead at the top of the table.
Craig Cachopa and Luke Wright contributed 53 and 52 respectively to further aid Sussex, while Ryan Sidebottom, Jack Brooks and Steven Patterson each took two wickets for Yorkshire.
The White Rose will be boosted by second-placed Nottinghamshire's struggles in Northamptonshire, who were grateful for Adam Rossington and David Willey as they enjoyed one of their better days of this season's championship.
Rossington scored 103, his maiden championship hundred, as his side posted 260 all out before Willey picked up three crucial top-order wickets to leave Nottinghamshire's reply in disarray on 38 for four at Wantage Road.
Ian Westwood hit his first century for two years to lead Warwickshire to 334 for nine against Somerset at Taunton.
The opener made the most of being dropped on 24 to score 129 after his side had lost the toss on a green pitch. Rikki Clarke contributed 42 to a sixth-wicket stand of 67, while Richard Jones made 35.
A fine 84 by Calum MacLeod and an attacking 83 from John Hastings helped Durham stage an impressive fightback against fellow strugglers Lancashire to reach 329 for eight at Old Trafford.
Durham looked in some trouble as they slipped to 82 for five but MacLeod and Hastings joined forces in a 145-run stand for the seventh wicket to help turn the clash around.
In Division Two, promotion favourites Worcestershire endured one of their worst days of the summer when they were dismissed for 194 by Gloucestershire on a seaming surface at New Road.
Having come into the match with a game in hand and 43 points ahead of second-placed Surrey, they are already looking at a sizeable deficit after the visitors' smooth progress to 181 for two.
In contrast, Surrey batted themselves into a strong position against bottom-of-the-table Leicestershire at Grace Road with Steven Davies scoring an unbeaten 147 - his second championship century of the season - and Vikram Solanki 93 in an imposing total of 403 for eight.
Sean Ervine's unbeaten 75 plus Chris Wood's 61 helped Hampshire to 343 for seven against Kent at Canterbury, while Jim Allenby returned figures of five for 56 as Essex were all out for 286 against Glamorgan, who closed on 27 for one at Swansea.