Kyle Verreynne's unbeaten 111 helped Nottinghamshire battle back against Essex's fast start on day one at Trent Bridge in Division One of the County Championship.
Essex ripped through the hosts' top order and left them 78-5 before lunch as Jamie Porter and Sam Cook each claimed two wickets.
Jack Haynes, Lyndon James and Fergus O'Neill helped to steady the ship alongside South Africa international Verreynne.
Verreynne recorded his 15th first-class century and hit 14 fours in his second three-figure score for Notts, who ended the day 328-8.
Durham opener Ben McKinney stayed calm as batters fell around him as his unbeaten 143 took the hosts to 343-7 against Warwickshire.
Durham lost three wickets for five runs in two overs to fall from 229-4 to 234-7. Colin Ackermann started the mini collapse before Will Rhodes went for a third-ball duck and Ben Raine was bowled by Vishwa Fernando.
But McKinney held his nerve to reach his second County Championship three-figure score, while England's Matthew Potts posted an unbeaten 53 before the close of play.
Dom Sibley notched his seventh century for Surrey as he remained unbeaten on 100 in a total of 253 all out against Hampshire.
Hampshire reached stumps on 55-1 in reply.
Daniel Hughes, Tom Clark and John Simpson all fell narrowly short of half-centuries as Sussex were bowled out for 294 by Somerset, who then struggled in their reply.
Archie Vaughan, Sean Dickson, Tom Abell, Tom Banton and Josh Davey were all dismissed as Somerset ended the day 62-5.
Dawid Malan fell two runs short of his 31st first-class century but helped Yorkshire post 425-8 against Worcestershire.
The 37-year-old edged Jacob Duffy's new-ball delivery into the hands of Ethan Brookes when on 98, while Adam Lyth and George Hill posted half centuries at Headingley.
England opener Zak Crawley's tough start to the season continued as he lasted just four balls as Kent fell to 79-6 at one stage in reply to Middlesex's 222 in Division Two.
But Harry Finch and Grant Stewart steadied things down and they were both closing in on half centuries at stumps with Kent 172-6.
Crawley was pinned lbw by Toby Roland-Jones for a duck to follow up his low-key scores from week one.
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