Steve James struck the first double century of his career as Glamorgan reached 439 for 5 by the close against Leicestershire at Grace Road, where the first day was washed out.
James reached his 200 in 352 minutes, from 304 balls and struck 30 fours. He went on to reach 230 not out, eclipsing the efforts of Matthew Maynard (103) with whom he added 242 for the third wicket.
Andy Caddick hit a career-best 92 as the Somerset tail wagged at New Road, taking the home side to 425 against Worcestershire. Jason Kerr made 42, adding 117 for the eighth wicket with Caddick. Phil Newport finished with 5 for 105.
Worcestershire's openers Tim Curtis and Phillip Weston got the home side's reply off to a fine start with a century opening stand before Weston went for 60. Curtis remained unbeaten on 46 at the close with Worcestershire 121 for 1.
The spinners Peter Such and John Childs helped Essex to a first-innings lead of 36 over Derbyshire at Chelmsford. Such claimed 5 for 86 and Childs 4 for 81 - including his 1,000th first-class wicket - as the visitors were dismissed for 290.
Phil DeFreitas, captaining Derbyshire, made 91 to help his side avoid the follow-on while Adrian Rollins scored 48 to complete 1,000 runs in a season for the first time in his career.
Essex added nine to their overnight 315 for 8 before Childs went for three. That left Australia's Mark Waugh stranded on 121 not out - a 180- ball century which included 15 fours and two sixes. By the close, Essex had reached 40 for 1, a lead of 76.
Paul Whitaker scored 88 and Shaun Udal was unbeaten on 45 as Hampshire made 333 against Nottinghamshire at Trent Bridge. The home side slumped to 142 for 9 - 191 behind - at the close after Udal took 5 for 77.
A rapid century by Courtney Browne lifted the West Indian tourists to 426 all out, made from only 79.3 overs on the first day of their three- day match against Yorkshire at the Scarborough Festival.
This followed an early collapse in which Darren Gough and Peter Hartley reduced the tourists to 25 for 3 in the first six overs. But Keith Arthurton (94) and Junior Murray (84) launched the recovery with a stand of 190 in 43 overs.Reuse content