Despite another day of rain delays and damp outfields, the third round of the Bob Willis Trophy is still conjuring up some impressive performances in the curtailed county season.
Somerset already seem to have one foot in the final after taking themselves to the brink of another emphatic victory.
Meanwhile the day was also notable for some career-best achievements with both bat and ball.
Dawid Malan scored a maiden double century as the productive start to his Yorkshire career continued while a potential future England quick in Sussex's George Garton claimed a five-wicket haul for the first time in the first-class game.
The meeting of the group's top two sides between Yorkshire and Derbyshire seems to be heading for a draw after just one over's play was possible on the second day.
Yorkshire made up for that lost time to move their first innings on from 288-4 before declaring on 400-6.
England international Malan was finally dismissed for a career-best 219 - a 244-ball knock which included 28 fours and four sixes.
Jonny Tattersall (66) helped push the White Rose to maximum batting bonus points as he and Malan put on a round 200 for the fifth wicket.
Derbyshire's reply featured a patient half-century from captain Billy Godleman (54) but nobody else could push after making a start as the visitors reached 198-6 by stumps.
While they still trail by 202, Yorkshire will likely have to bat again with the follow-on target 200 in this competition. That would take out a considerable chunk of the final day to set up their hopes of a third successive win.
An innings victory could still be on the cards at Trent Bridge though where Nottinghamshire are in command against Lancashire.
After no play was possible on Sunday due to rain, Notts pressed on with their first innings from 268-2 overnight before eventually being bowled out for 472.
Opening-day centurion Ben Slater was eventually dismissed for 142 while captain Steven Mulaney (67) and Joe Clarke (57) helped take advantage of a weary and inexperienced Lancashire attack.
Lancashire stuttered in reply, finding themselves in early trouble at 59-4 as Keaton Jennings (10) and Liam Livingstone (14) both departed cheaply.
More wickets in the evening sunshine for Nottinghamshire saw them reduce Lancashire to 129-6 when play ended at 19:30 BST.
Steven Croft (37 not out) will need to continue to play a vital hand with his side still 343 behind and 144 runs shy of avoiding the follow-on.
Only 8.5 overs were possible on another soggy day at Grace Road between Leicestershire and Durham.
Durham lost Paul Coughlin for a duck to Gavin Griffiths before a series of torrential downpours led to large pools of water on the outfield and an abandonment by early afternoon with the visitors on 250-7.
Somerset need just four more Warwickshire wickets to complete their third win in three matches.
Steven Davies (123 not out) and Jamie Overton (120) put them in a commanding position earlier in the day with a 180-run partnership for the ninth wicket.
Overton, who will join Surrey next season, smashed 15 fours and six sixes in his 92-ball maiden first-class century while Davies played the perfect foil during the onslaught.
It meant Somerset were eventually able to declare on 413-9 with maximum batting bonus points and a lead of 292.
It didn't take long for their five-pronged seam attack to get among the wickets again as the Bears slumped to 58-5, including two wickets in two balls from Josh Davey.
Skipper Will Rhodes (41) saw his rearguard effort come to an end shortly before a rain shower curtailed play with Warwickshire on 104-6, still 188 runs shy of making Somerset bat again.
Despite losing a considerable chunk of the game to rain, Northamptonshire and Worcestershire have still managed to serve up a delicately-balanced contest.
Northants resumed on 90-4 still 129 behind Worcestershire's first-innings 219, but quickly found themselves in trouble at 100-7.
Gareth Berg (45) and Nathan Buck (32) steered them through some valuable partnerships of 59 and 34 for the eighth and ninth wickets before Berg was last man out, one of Joe Leach's three victims as Northants fell seven runs shy of parity on 212.
By stumps, it was still unclear who was in the ascendancy.
Tom Fell (81 not out) remains well set for Worcestershire after sharing partnerships worth 67 and 59 alongside Daryl Mitchell (39) and Jack Haynes (32) for the second and third wickets.
They hold a 189-run lead with four wickets in hand but Buck (3-30) continued his profitable day picking up crucial late breakthroughs for Northants as Worcestershire closed on 177-6.
Glamorgan suffered a batting collapse and then a potentially season-ending injury to one of their frontline bowlers as Gloucestershire continued to enjoy the better of their fixture at Cardiff.
The hosts were dismissed for just 116 with David Payne taking 5-31 as Glamorgan lost their last five wickets for just 36 from their overnight position.
Problems soon mounted when Timm van der Gugten was forced off the field with a dislocated finger having already taken two wickets.
But a determined effort from the rest of the bowlers saw Gloucestershire bowled out for 181 to restrict their lead to 65. Graham Wagg took 3-38 while Ryan Higgins (48) and Tom Lace (42) led the way with the bat.
Nick Selman and Charlie Hemphrey then negotiated 14 overs unscathed in Glamorgan's second innings to steer them to 23-0, which means they trail by 42 runs.
At Hove, after just 61 overs were possible on the first two days, Sussex and Essex more than made up for lost time to move their game on.
Essex took four quick wickets as Sussex were dismissed for 194 as Jamie Porter finished with 5-60. But the group leaders made just 140 in reply as left-arm seamer Garton was the stand-out performer.
Garton, 23, bowled with pace and bounce to take 5-26, which included the key scalps of Sir Alastair Cook and Dan Lawrence, to hand his side a 54-run lead.
Despite losing Tom Haines cheaply, Phil Salt (18 not out) and Harry Finch (32) compiled a 50 partnership to push that lead up to 111. Finch fell to the final ball of the day at 57-2, but Sussex look the more likely to set up a victory charge on the last day.
After passing 800 career wickets on Sunday, the seemingly never-ending Darren Stevens story continued between Kent and Middlesex.
Stevens completed his 28th five-wicket haul in first-class cricket with 5-79 as Middlesex recovered from a perilous-looking 123-6 overnight to make 269.
Robbie White agonisingly fell one run shy of what would have been his maiden first-class century when Stevens ended his 220-ball stay courtesy of a juggling slip catch from Jack Leaning.
Fred Klaassen's career best 4-44 provided a perfect partnership for Stevens as James Harris (41) was the only other Middlesex batsman to settle.
In reply, Joe Denly made the most of his first innings in county colours this summer with an unbeaten 70 from 124 balls. Miguel Cummins (3-41) was the pick of the Middlesex bowlers as Kent closed on 146-5.
They still trail by 123 and a draw, which will suit neither side's hopes of moving up the group, appears the most likely outcome.
At Arundel, Hampshire's best hope of forcing a win against Surrey will be scoring quick runs on the final morning before praying for another Surrey batting collapse.
Surrey's first innings was finally concluded on 172 after Morne Morkel frustrated Hampshire's bowlers with 33 off 25 balls, including seven fours.
But Hampshire's reply featured some valuable partnerships from their top order. Stand-in skipper Sam Northeast (81), opener Joe Weatherley (36) and Tom Alsop (52 not out) all made crucial contributions to steer them to 198-3, which is a lead of 26 runs.