After deciding not to enforce the follow-on when leading by 246, Warwickshire lost five wickets for 75 before a stand of 104 by Chris Woakes (60) and Rikki Clarke (54) set up a declaration at 180 for six. Needing 427 in 107 overs, Nottinghamshire reached 38 without loss at stumps heading into the final day.
At Chesterfield, Alex Lees celebrated his new contract with a career-best unbeaten 171 as Yorkshire dominated the opening day against Derbyshire. Lees scored his second Championship hundred in three games and shared a Yorkshire record second-wicket stand against Derbyshire of 311 with Phil Jaques, who made 139.
The title contenders closed on 367 for two, adding up to another tough day for the bottom team in Division One.
Ed Joyce hit a century as Sussex were bowled out for 229 inside 81 overs on the first day against Middlesex at Hove.
Joyce's spirited 101 from 166 deliveries was the stand-out performance for the hosts, for whom opener Chris Nash weighed in with 40 runs before he fell victim to Gareth Berg (three for 49). In reply, Middlesex were 34 without loss at stumps.
In Division Two, James Fuller became only the fourth Gloucestershire player to take a hat-trick at Cheltenham as Worcestershire were bowled out for 182 on the opening day.
The visitors crashed to 22 for six, Fuller removing Matthew Pardoe with the final ball of the eighth over and then striking with the first and second deliveries of the 10th, sending back Moeen Ali and Alexei Kervezee.
Joe Leach came to Worcestershire's rescue with a career-best 82 not out, sharing a seventh-wicket stand of 120 with Gareth Andrew, who made 54. Fuller finished with five for 43 from 19 overs. By the close, the home side had made a confident start to their reply and were 83 without loss, Chris Dent unbeaten on 56 and Michael Klinger 27 not out.
Ashwell Prince and Simon Katich both scored centuries as leaders Lancashire saw their contest with Glamorgan head towards a draw at Old Trafford.
The pair shared 157 runs in 42 overs for the third wicket as Lancashire ended day three on 423 for five in reply to Glamorgan's first-innings 474.
A draw also looks the most likely outcome at Canterbury where centuries from Rob Key and Brendan Nash helped Kent through to an impressive 513 and a first-innings lead of 108 in a high-scoring clash with Hampshire.
Key eventually fell for a season-best 180, while Nash hit 126 during his near four-hour stay at the crease as Kent posted their best first-innings total of the season.
Hampshire reached 15 without loss before the close and will go into the final day trailing by 93 runs.
At Chelmsford, Ned Eckersley full advantage of a friendly pitch to collect his second century of the season as Leicestershire made 328 for four on the opening day against Essex.
The right-hander combined disciplined defence with controlled aggression as he reached the close on 133 not out, including 15 fours and two sixes off 236 deliveries.