An unbroken fifth-wicket partnership of 206 enabled current leaders Kent to hit back on the second day of their match against Surrey at Guildford.
Replying to the hosts' 452 for eight declared, they closed just 44 runs adrift on 408 for four - chiefly thanks to the efforts of Matthew Walker (134 not out) and Justin Kemp (114no).
Walker hit 18 fours and two sixes with Kemp managing 17 boundaries and one six - after England discard Robert Key had got the innings off to a good start with 65.
Earlier, Ali Brown added just six runs to his overnight score of 101, while Azhar Mahmood moved on to 41 as 14.4 overs yielded 58 runs for Surrey.
Sussex finished the second day of their clash with Hampshire at the Rose Bowl in a strong position.
Hampshire moved on from their overnight 293 for seven to 309 all out, with Nic Pothas eventually dismissed for 135.
Sussex then made 316, with Richard Montgomerie (64) the chief contributor with the bat and Sean Ervine starring with the ball with five for 73.
But Hampshire lost three wickets for one run in slipping to 22 for three in their second innings - with James Kirtley taking two of the wickets to fall.
On the first day at Sophia Gardens, Owais Shah's century provided a solid foundation as Middlesex scored 396 for six against Glamorgan.
Shah made 101 from 152 deliveries, including 11 fours, and shared a second-wicket stand of 109 with Ben Hutton, who made 73.
In Division Two, Leicestershire bowled out Yorkshire for 187 at Scarborough for a first innings lead of 179 runs.
Ottis Gibson, Charl Willoughby and Stuart Broad each took three wickets, while Ismail Dawood top-scored for Yorkshire with 45.
Captain HD Ackerman opted not to enforce the follow-on and Tim Bresnan then captured openers Darren Robinson and Darren Maddy for ducks.
John Maunders (48) and Australian Chris Rogers - 35 in his last championship appearance for the county - consolidated and at the close on day two the visitors were 106 for five, and holding a healthy overall advantage of 285.
Leaders Durham took control of their clash with bottom county Derbyshire on the opening day, before a late slump took the edge off their earlier efforts.
After winning the toss, visitors Durham moved to 309 for three thanks chiefly to England international Paul Collingwood's 190 from 255 balls - which included 28 fours and two sixes - and Dale Benkenstein's 98.
But the departure of Benkenstein sparked a slide which saw Durham close on 363 for nine, with Nick Walker (four for 64) the pick of the Derbyshire bowlers.
Essex made decent progress in their clash against second-placed Lancashire at Old Trafford with the toss again helping the visitors. Grant Flower top-scored with 115 in their score of 279 for four, with elder brother Andy (62 not out) returning to the crease this morning.