Tom Banton’s third first-class century saw Somerset claim opening day victory over Surrey in the Vitality County Championship top-two clash.
Banton fell one run short of his career-best tally of 132 as his side posted 317 runs overall after the visitors fought back, having seen their second-placed opponents reach 305 for five at one stage.
This was mainly thanks to the four wickets of Bangladesh spinner Shakib Ul Hasan, signed only for this match, and the three wickets of Dan Worrall for 41.
Essex captain Tom Westley’s 108 not out was the mainstay of the fourth-placed side’s 262 for five against Nottinghamshire at Chelmsford.
He shared a fourth-wicket stand of 142 with Paul Walter (72) to steer his team away from trouble.
Ninth-placed Lancashire’s relegation fears intensified after Durham’s Ben Raine took four wickets to reduce them to 177 for six and they were only spared by Matthew Hurst’s unbeaten 74, with 49 coming from Josh Bohannon.
Hampshire captain James Vince provided the only resistance with 88 as Kent reduced the visitors to 213 for seven on a rain-shortened day.
No other player took more than 31 wickets as Matt Parkinson (three for 31) and George Garrett shared six wickets.
Worcestershire captain Brett D’Oliveira hit his fourth consecutive half-century since returning from a shoulder injury as the hosts recovered from 67 for four in the mid-table battle at home to Warwickshire to close on 294 for eight.
Division Two leaders Sussex boosted their promotion hopes after left-handed seamer Jaydev Unadkat picked up four for 52 as Glamorgan were dismissed for 186.
The hosts reached stumps at 121 for one after an opening century between Daniel Hughes (57no) and Tom Haines (48).
Eighteen wickets fell on the first day as promotion-chasing Yorkshire got the better of Leicestershire.
The hosts slumped to 15 for seven in the first hour but recovered to 98 thanks to 51 not out from Ben Cox.
Paceman Ben Coad took five for 15 before Yorkshire captain Jonny Tattersall guided them to 263 for eight in reply.
Jack Davies’ highest first-class score of 91 helped Middlesex reach 377 all out after being bowled out by Gloucestershire at Lord’s.
The Middlesex left-hander shared a sixth-wicket partnership of 120 with Josh de Caires (64), with Max Holden making 77 at number three, while Tom Price and Ajeet Singh Dale shared nine wickets.
All seven Derbyshire bowlers claimed at least one wicket as Northamptonshire were bowled out for 219 in the bottom two clash, with only Saif Zaib (90) and Justin Broad (45) making an impact.
Zak Chappell and Martin Andersson were the best bowlers with two each as the visitors finished on 65 for one in reply.