Rory Burns became the first player to pass 1,000 Specsavers County Championship runs this season as Division One leaders Surrey started well against Essex at Chelmsford.
The Surrey captain, who has been tipped for an England call, scored 90 and shared in a third-wicket stand of 148 with Dean Elgar (75) as the visitors reached 256 for four at the end of the first day.
Ben Foakes (24 not out) and Will Jacks (15no) will resume on Wednesday after Essex fought back with three wickets late in the day.
Lancashire were in deep trouble against Somerset at Taunton after again failing to fire with the bat.
England hopeful Jack Leach took five for 28 as the visitors were skittled for just 99 on day one.
Somerset did initially struggle in reply, slipping to 97 for seven at one point, but a spirited unbeaten 64 from Lewis Gregory helped them to 192. Lancashire were seven for two in their second innings at stumps, Leach again having struck twice.
Ben Slater’s 109 helped Nottinghamshire reach 332 for seven at the end of the first day against Yorkshire at Trent Bridge.
Slater put on 182 for the first wicket with Kraigg Brathwaite (71) while Ben Duckett also weighed in with 80.
Matthew Waite took three for 72 as Yorkshire remained competitive.
Ed Barnard claimed six wickets for 50 as Hampshire, for whom Sam Northeast top-scored with 48, failed to make the most of winning the toss.
Worcestershire struggled to build on that fine start, slipping to 68 for four in reply.
In Division Two, promotion-chasing Kent also hit back after being shot out for 137 in another low-scoring encounter.
Ben Sanderson, Nathan Buck and Richard Gleeson each took three wickets as Northamptonshire took charge early on at Canterbury, but the tables were soon turned.
Northamptonshire collapsed to 71 for eight in reply, before bad light stopped play, after six for 31 from Matt Henry.
Meanwhile, leaders Warwickshire ended the first day against Durham at Edgbaston on 184 for six.
Jonathan Trott was unbeaten on 67 on a day when only 68 overs were bowled.
Bottom side Glamorgan bowled Derbyshire out for 251 at Derby thanks to three wickets apiece from Timm van der Gugten and Graham Wagg. Billy Godleman fell five short of a century.
Glamorgan closed on 20 without loss.
Chris Jordan was unbeaten on 52 as Sussex reached 323 for eight against Leicestershire at Hove.
Tom Haines (56), Luke Wells (58) and Ben Brown (60) earlier hit half-centuries.
Gloucestershire ended the first day of their clash with Middlesex at Bristol on 208 for seven. Chris Dent led the way for the hosts with 82.