Luke Wright and Ben Brown were in record-breaking form as Sussex reached 441-5 against defending champions Durham in LV= County Championship Division One.
The pair came together with the hosts at 115-5 and remained there at the close having put on 326 runs. The partnership is Sussex’s highest for the sixth wicket, beating a record set in 1930, and the highest sixth-wicket stand for anyone against Durham.
Wright, on 183, is just four runs short of equalling his highest first-class score, while Brown ended the day unbeaten on 152, 40 runs more than his previous best.
The wicketkeeper, who is standing in for the injured Matt Prior, was dropped by his opposite number Phil Mustard before reaching his half-century.
Neil Dexter led the Middlesex attack as he claimed six Lancashire wickets at Lord’s.
Jos Buttler and Tom Smith each hit 59 as the visitors mounted a middle-order comeback before they were eventually bowled out for 266.
Dexter, more noted for his batting prowess, returned career-best figures of 6-63.
Michael Carberry hit an unbeaten half-century to put Hampshire in the ascendency on day one of their Division Two match with Glamorgan at the Rose Bowl.
The England batsman racked up only his second score of 50 or more this season, ending the day on 62 not out in the hosts’ 119-1 in reply to Glamorgan’s 224.
Kyle Abbott, Matt Coles and Sean Ervine earlier claimed three wickets each, Ervine returning marginally the better figures of 3-36.
Captain Mark Wallace made an unbeaten 67 for Glamorgan but their total after losing the toss and being put in to bat looked well short.
Surrey’s Matt Dunn returned career-best figures but Gloucestershire struck back with the ball to leave the clash at the Kia Oval finely poised after 16 wickets on day one.
Dunn took 5-48 in Gloucestershire’s total of 168 to eclipse his haul at Derby in 2011.
But James Fuller then took four wickets to reduce the hosts to 62-6 before Jason Roy and Chris Tremlett steadied things to reach 118 for no further loss by the close.