Kumar Sangakkara's fifth successive first-class ton led Surrey's recovery against Division One leaders Essex.
The Sri Lankan finished day one unbeaten on 177 as Surrey closed on 334 for seven, having been reduced to 31 for five before lunch.
Sam Curran chipped in with 90 in a 191-run sixth-wicket partnership with Sangakkara as Essex toiled in the field on a baking afternoon in Chelmsford.
Elsewhere in Division One Jack Leach took six wickets to put Somerset in charge against Hampshire at Taunton.
Leach registered six for 78 and fellow spinner Dom Bess took three for 45 to skittle Hants for 162.
George Bailey and Kyle Abbott offered some resistance but both fell infuriatingly one run short of half-centuries.
Dean Elgar then hit 60 as Somerset ended day one on 157 for five, trailing by just five runs with five wickets remaining.
In Division Two centuries from Cheteshwar Pujara and Michael Lumb helped put leaders Nottinghamshire in control against Gloucestershire at Trent Bridge.
India Test batsman Pujara scored 112 and Lumb added 117 as Notts piled up 357 for five after being asked to bat.
Joe Denly's first hundred of the season helped Kent recover from a poor first session to reach 316 for eight against Sussex.
Denly hit 119 in a five-hour stay at the crease as Kent rallied after losing three wickets in the morning session.
Daryl Mitchell's unbeaten half-century made it Worcestershire's opening day at Wantage Road.
After Northamptonshire were bowled out for 238, Mitchell's 52 not out steered the visitors to 108 for two by the close.
Paul Collingwood hit 127 on his 41st birthday but Durham lost their final four wickets for no runs at Glamorgan.
Michael Hogan took five for 49 as Durham missed out on a fourth batting bonus point for reaching 350.
Skipper Billy Godleman led Derbyshire's reply after Leicestershire passed 600 on the second day at Derby.
Godleman marked his 50th first-class appearance for the county with an unbeaten 60 as Derbyshire closed on 154 for one, still 465 runs behind, in reply to Leicestershire's 619 all out.
Leicestershire captain Mark Cosgrove top-scored with 188, adding 239 inside 38 overs with Ned Eckersley, who made a career-best 158.
Source: PA
