Hampshire are in a great position against Nottinghamshire in the First Division match at the Rose Bowl after centuries from John Crawley and Nic Pothas.
Crawley was unbeaten on 100 as Hampshire reached 345 for 5 before the close. Pothas, who put on 217 with Crawley for the fifth wicket, hit 117 before falling to Andy Harris late in the day.
Fifteen wickets fell at Edgbaston, where Durham were reduced to 73 for 5 after bowling Warwickshire out for 208. Ottis Gibson and Graham Onions took seven wickets between them as Warwickshire struggled. Heath Streak and Lee Daggett responded by taking two wickets apiece to keep the hosts in the game.
In the Second Division, Australian Mark Cosgrove put Glamorgan in a commanding position on the second day against Derbyshire at Derby. Cosgrove was unbeaten on a career-best 233 as Glamorgan closed with a lead of 51 on 378 for 3. Derbyshire were earlier bowled out for 327, with Robert Croft finishing with five for 56.
Graeme Hick made a brilliant return to form on the first day of Worcestershire's game with Somerset at Taunton. Hick was unbeaten on 151, sharing a stand of 274 with Ben Smith as Worcestershire piled on the runs. The visitors were 444 for 3 at stumps with Smith 121 not out.
Four wickets from Rikki Clarke gave Surrey the edge against Leicestershire at the Oval. Clarke wrapped up the tail to claim 4 for 45 and finish Leicestershire off for 251. Surrey were 64 for 1 in reply at stumps.