Former England captain Ben Stokes made a half-century as Durham ended their opening day against Worcestershire 437-7 in an innings where Mayank Agarwal made a superb 177 in the County Championship.
have already been crowned Division Two champions and secured promotion, but that did not stop them piling on the runs at The Riverside, with wicketkeeper Ollie Robinson (78 not out) also enjoying a good day with the bat.
In Division One, - battling for survival - reduced to 132 all out, but then mustered just 115 in reply as 20 wickets fell on the opening day at The Oval, with the visitors reaching 30 without loss in their second innings to lead by 47 runs at close of play.
At the top of the table, Ethan Bamber and Sam Hain ensured maintained their title challenge by ending the first day against with a 17-run lead with one wicket in hand.
Seamer Bamber took six for 26 at Chelmsford to help skittle Essex for 134 and as wickets continued to tumble in Warwickshire's reply, Hain was unbeaten on 58 as the visitors closed on 151 for nine.
Warwickshire began the penultimate round of fixtures in third place, five points adrift of leaders and four adrift of defending champions , while conditions up and down the country favoured the bowlers.
Somerset's Lewis Gregory, Migael Pretorius and Jake Ball took three wickets each as they bowled out for 212 at Headingley, but the visitors then laboured to 68 for five and trailed by 144 at the close.
teetered on 150 for eight against at Hove before Brett Hutton (59 not out) and Tom Giles (32) shared a 74-run ninth-wicket stand, with the visitors set to resume on 232 for nine.
skipper Ian Holland claimed six for 38 as relegation rivals were bustled out for 214 at Grace Road - Nathan Gilchrist adding four for 54 while visiting captain Ben Brown made a defiant 80 not out - before Hamza Shaikh (50no) helped the hosts reach 148 for seven in reply, 66 runs behind.
Bangladesh seamer Khaled Ahmed took five for 42 on his home debut for promotion-chasing at Canterbury in Division Two, and Matt Milnes finished with four for 28 as were bowled out for 161.
Kent opener then made an unbeaten 68 to help the hosts reach 151 for seven, 10 runs behind with three wickets remaining as James Anderson and Tom Bailey took three apiece.
Promotion rivals allowed to buck the trend as captain Wayne Madsen (151) and number eight Ben Aitchison (106) both made centuries to help the visitors reach 372 all out. Northamptonshire were 15 without loss at close and will resume 357 runs behind.
closed on 324 for nine in Bristol against bottom side .