The defending champions were 55 for four at lunch at Headingley with Steven Patterson claiming two wickets for just three runs in the first session.
Yorkshire could only add eight runs to their overnight score of 294 for nine, but the wickets of Warwickshire batsmen Varun Chopra (23), Ian Westwood (seven), William Porterfield (nine) and Tim Ambrose (nought) left them in a strong position.
Wickets continued to tumble at Lord’s, with Middlesex all out for 168 in their first innings after starting the second day on 88 for five in reply to Durham’s 143 all out. Graham Onions impressed with figures of seven for 62 as Middlesex were bowled out cheaply, with Neil Dexter’s 48 the best showing with the bat. Durham started their second innings and lost three wickets within 14 overs before lunch to give them a slender lead of 18. Mark Stoneman (nought), Keaton Jennings (two) and Scott Borthwick (26) were the men out, with Steven Finn and Tim Murtagh making the breakthroughs.
Somerset lost an early wicket as they began their reply to Nottinghamshire’s first innings total of 378 at Taunton. Notts resumed on 327 for eight with number nine Luke Fletcher the last man out after adding a useful 58 to the visitors’ total. It meant Somerset had a tricky period to face before lunch, and they lost the wicket of Marcus Trescothick in the eighth over for two, leaving them at 20 for one at the break.
Derbyshire trailed by 233 runs in the first innings at lunch in their match with Sussex after losing four wickets. Sussex were all out for 314 on Friday, but Derbyshire’s reply got off to a less-than-perfect start with Ben Slater (16), Chesney Hughes (13), Shivnarine Chanderpaul (nine) and Richard Johnson (one) all falling to leave the visitors teetering at 81 for four at the break.
In Division Two, Hampshire were dismissed for 349 by Glamorgan on the stroke of lunch after starting the day six down for 261..
Leicestershire lost an early wicket in their reply to Lancashire’s first-innings 380 at Grace Road. Greg Smith was dismissed off the bowling of Kyle Hogg to leave the hosts 21 for one after Lancs lost their last five for 77 runs, with Ollie Freckingham picking up figures of four for 85.
Northamptonshire were 112 without loss in their reply to Gloucestershire’s 358 at the County Ground.
An early lunch was taken at New Road with rain delaying the start of Worcestershire’s first innings in response to Kent’s 318.