James Anderson clinched the 54th five-wicket haul of his first-class career before Lancashire's batters piled on the runs against Somerset in Division One of the LV= Insurance County Championship.
Anderson, 40, added James Rew (117), Lewis Gregory (5) and Kasey Aldridge (14) to his day-one dismissals of Tom Lammonby (15) and Sean Dickson (0) as Somerset were bowled out for 441 - Tom Abell top-scoring with 151 - having resumed on 311-4 at Taunton.
Lancashire opener Keaton Jennings then struck an unbeaten 124 against the same opponents he had notched a triple century against last season as the visitors closed on 302-1 from 59 overs to trail by just 139, with England spinner Jack Leach taken for 103 from a wicketless 17 overs.
Jennings added 154 with Luke Wells (82) while his second-wicket stand with Josh Bohannon (73no) had reached 148 by stumps.
England opener Ben Duckett turned his overnight 119 into 177 as Nottinghamshire made 364 all out at Lord's before hosts Middlesex reached 111-2 thanks chiefly to Mark Stoneman (60no) - Stuart Broad trapped Pieter Malan lbw for 26 from the final ball of the day.
Elsewhere in Division One, captain James Vince's 186 propelled Hampshire to 482-8 declared against Northamptonshire before his side reduced their opponents to 95-5 at the County Ground.
Vince spent almost six-and-a-half hours at the crease, sharing a century stand with Ben Brown (55) for the sixth wicket.
Mohammad Abbas trapped Ricardo Vasconcelos (0) lbw from the first ball of Northants' reply while the hosts then lost three wickets in five balls to slip from 47-1 to 48-4.
Tom Westley (138no) and Nick Browne (105no) hit centuries as Essex advanced to 289-1 against Kent at Canterbury on a day on which just 32 overs were possible due to the weather.
In Division Two, Sussex have the advantage against Yorkshire at Hove after posting 361 all out and then reducing their visitors 216-7.
Spinner Jack Carson starred for Sussex, sharing a last-wicket stand of 57 with Harry Crocombe from 304-9 and then taking three Yorkshire wickets, including Dawid Malan (37) and Shai Hope (38).
Yorkshire seamer Ben Coad earlier completed a five-wicket haul after Sussex resumed on 275-5.
Elsewhere, the wet weather prevented any play in the games between Worcestershire and Gloucestershire at New Road and Glamorgan vs Durham in Cardiff.
