A Michael Yardy century put Sussex on course for victory in their LV= County Championship Division One match against reigning champions Lancashire.
The left-hander added 40 runs to his overnight 70 as the visitors made 300 in reply to Lancashire's 124 all out, ensuring a commanding first-innings lead of 176 after two days in Liverpool.
In compiling his 18th first-class century, Yardy stifled home hopes of early wickets with some dogged batting to advance their overnight score from 137 for three.
Australian debutant Steve Magoffin then ripped through Lancashire's top order after tea with three wickets to reduce them to 39 for three in their second innings.
Michael Lumb's ton put Nottinghamshire in command against Durham at Chester-le-Street.
The 32-year-old left-hander survived a sticky start in difficult morning conditions then prospered on a sunny afternoon to remain unbeaten on 104.
He put on 85 with Alex Hales and 99 with James Taylor to take Notts to 231 for four, a lead of 263.
Nick Compton continued his run-packed start to the season by keeping Somerset afloat in a hard-fought clash with last year's runners-up Warwickshire at Edgbaston.
Having made 236 against Cardiff University and 99 against Middlesex, he followed up with another half-century as the West Country side edged into a lead of 31 on reaching 127 for four.
Somerset trailed by 96 runs from the first innings after being skittled for 147 and then were frustrated as the Warwickshire tail helped the hosts to 243 in reply, but Compton's unbeaten 61 will give them hope heading into day three.
Surrey's top order limped to the close on 161 for five to still trail Middlesex by 95 at the mid-point of the match at Lord's.
Responding to a Middlesex first-innings total of 256 all out, Surrey struggled for timing on a pitch that offered seam assistance to Tim Murtagh, Corey Collymore and Toby Roland-Jones, who all tasted success.
Surrey started brightly enough with Jacques Rudolph (45) and Steven Davies (62) putting on 85 for the opening wicket, but their demise triggered a collapse that saw the likes of Mark Ramprakash and Zander de Bruyn (both 17) removed cheaply.
In Division Two, all-rounder Jon Clare took five for 17 and contributed an unbeaten 40 with the bat as Derbyshire took the upper hand against Glamorgan at the Swalec Stadium.
Derbyshire ended on 152 for six in their second innings, an overall lead of 187 after bowling Glamorgan out for 95.
At Wantage Road, Mike Powell scored his first century in the County Championship for three years as Kent took control on the second day against Northamptonshire.
In just his second game since his move from Glamorgan, Powell hit an unbeaten 128 off 227 balls, including 19 fours, as Kent were bowled out for 368.
Jack Brooks was by far the most effective bowler in taking five for 98 before Northants struggled in reply to close on 50 for four, 186 runs behind the visitors.
Pace bowler David Balcombe took a career-best eight for 71 but Hampshire struggled to make the most of his achievement as Gloucestershire fought back at the Ageas Bowl.
The hosts were held up by Gloucestershire opening batsman Chris Dent, who made a diligent 114, and the south coast team then limped to 182 for seven in reply to the visitors' 314, still trailing by 132 runs.