Thorp's five gives Durham command
Leaders Durham continued their domination of the LV= County Championship as they dismissed Warwickshire for 135 then reached 173 for four in reply at Chester-le-Street.
Callum Thorp earned his second five-wicket haul in successive home games, while Dale Benkenstein took three wickets and scored 59 not out.
Lancashire recovered from a dreadful start to the Roses match against Yorkshire to reach 226 for seven at the end of day one against Yorkshire at Headingley Carnegie.
Yorkshire stunned Lancashire with two wickets in three overs at the start of the match, but a fighting unbeaten 73 from Mark Chilton helped the visitors recover.
Adil Rashid took 3-76, including the wicket of VVS Laxman for 50.
An unbeaten 103 from Michael Lumb put relegation-threatened Hampshire in a strong position against Nottinghamshire at Trent Bridge.
The 29-year-old left-hander smashed 17 fours from 174 balls as the visitors piled on the runs to reach 345 for three at the close after winning the toss.
England Lions batsman Michael Carberry had also looked in good form, hitting 17 fours on his way to 86, but then retired hurt with a broken finger, while Jimmy Adams made 55.
Chris Nash struck his career-best score against Somerset for the second time this season as Sussex ran up 326 for three on a one-sided opening day at Taunton.
Having made 134 against the same opponents at Hove in June, the opener helped himself to 157 on a dry pitch that offered scant assistant to any bowler. Murray Goodwin contributed an unbeaten 96 after the visitors had won the toss.
In Division Two, Jack Brooks held up Derbyshire's promotion advance by marking his championship debut with a four-wicket haul on an eventful opening day against Northamptonshire at Chesterfield.
The 25-year-old seamer took four wickets for 76 runs as Derbyshire were bowled out for 255, before the visitors replied with 137 for three - Rob White hitting 62 off 56 balls.
Garry Park and Jamie Pipe hit half-centuries for the home side.
Teenager Josh Cobb celebrated his return to the side after a three-match absence with a sparkling 72 off 86 balls as bottom-of-the-table Leicestershire reached 332 for eight against Gloucestershire at Grace Road.
Veteran Paul Nixon and England Under-19 international James Taylor also hit half-centuries to steer the hosts beyond 300 in their first innings at home for the first time in five matches.
An unbeaten 87 from Chris Schofield and a career-best 61 for Matt Spriegel revitalised the Surrey innings as the visitors reached 304 for six by the close against Essex at Colchester.
Having won the toss and elected to bat, the visitors were in trouble, having lost half their wickets with only 136 on the board but Schofield and Spriegel turned things around with a stand of 127.