Somerset's Alfonso Thomas stunned Sussex with four wickets in as many balls to help his side go top of LV= County Championship Division One with a six-wicket win at Taunton on day three.
The 37-year-old returned five for 40 after becoming the first man since Surrey's Gary Butcher 14 years ago to take four in four, with James Anyon, Rory Hamilton-Brown, Ed Joyce and Matt Machan his victims.
Sussex had been 33 for nought but Thomas' intervention saw them slump to 33 for five then 178 all out, posting a meagre target of 103 which the table-toppers knocked off for the loss of four wickets.
A solid evening stand between Nottinghamshire's Michael Lumb (43no) and James Taylor (27no) left their clash with Yorkshire evenly poised at the end of day three at Headingley.
The pair, Lumb apparently in England's past and Taylor still fighting for a place in its future, added 72 in 25.3 wicketless overs to leave the visitors 60 ahead on 102 for two at stumps.
When they came together Nottinghamshire were still 12 in arrears with Yorkshire looking to ram home their advantage having earlier been dismissed for 247.
But an attack missing the pace of recalled England seamer Liam Plunkett could not part the third-wicket duo.
A draw appeared the likeliest outcome at stumps in the match between Warwickshire and Lancashire at Edgbaston, with t he away side closing on 84 two, a lead of 48.
The Bears turned their overnight 130 for four into 322 all out, Tim Ambrose (62), Rikki Clarke (56) and Keith Barker (44no) all chipping in with important runs.
Red Rose opener Paul Horton made 42 in a brisk first-wicket stand of 71 but he and partner Alex Davies both fell before the end.
Worcestershire spinner Saeed Ajmal was Hampshire's tormentor on day three of Division Two's top-of-the-table clash at New Road, taking eight wickets in the day with a stunning display of off-spin bowling.
Hampshire were made to follow-on after being bowled out for 219 in response to the Pears' mark of 402 for nine declared, Ajmal claiming seven for 63.
The 36-year-old then struck just before stumps to leave Hampshire on 31 for one at the close - trailing by 152 runs - and his side can leapfrog their opponents with victory on day four.
Rory Burns fell just one run short of a double-century as Surrey smashed a mammoth total of 626 for six against ragged Gloucestershire on day two in Bristol.
Zafar Ansari was also two short of a maiden first-class ton, Jason Roy blazed 121no and Vikram Solanki scored 143 as the Brown Caps racked up an imposing lead of 514 in reply to a now insignificant 112 all out.
David Wainwright impressed with bat and ball as rock-bottom Derbyshire moved into a good position on day three against Leicestershire at Grace Road.
Wainwright, who earlier completed his maiden century for the visitors, claimed five for 54 to leave the hosts struggling on 200 for nine after losing their first three wickets for just 34 runs.
That gave them a lead of just 175 and gave Derbyshire high hopes of a first win of the season at the expense of their fellow strugglers.
Part-time seamer Jesse Ryder claimed his second five-wicket haul of the match but the Essex attack could not break Kent down as their Division Two clash at Canterbury ended in a draw.
Kent came into the final day trailing by 18 runs but with all their second-innings wickets intact but ground their way to 225 for eight before declaring to end the match.
New Zealander Ryder did his bit, taking five for 56 to add to his five for 54 in the first innings, but a second half-century of the match from Daniel Bell-Drummond and 47 from first-innings centurion Darren Stevens meant Kent were never in real danger.