Surrey have retained the County Championship, winning the title for the 22nd time in their history.
The county's third title in the past six seasons was secured after their nearest challengers in Division One, Essex were bowled out for 211 in their first innings against Northamptonshire.
A 20-point gap between the top two heading into the final round of fixtures meant Surrey required just five points to claim the crown for a second successive year.
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Their failure to take any batting bonus points against Hampshire left the door slightly ajar for Essex, who needed to post a 400-plus score in 110 overs at Wantage Road to keep the title race alive.
Surrey have become the first side to retain the county title since Yorkshire's back-to-back victories in 2014 and 2015.
Essex needed four batting points to keep the title race alive but weren't able to get even one after Jamie Porter was bowled by Northamptonshire's fast bowler Tom Taylor for nought before lunch.
Surrey found out about winning their second title during their game against Hampshire just as Will Jacks was about to bowl.
Essex capitulate as Kent's future hangs in the balance
Essex were unable to claim the maximum amount of batting bonus points as they capitulated to 211 all out on Thursday morning, with last man Jamie Porter bowled by Tom Taylor to crown Surrey champions.
Essex were then dismissed for 119 in their second innings as relegated Northamptonshire bowed out of Division One in style.
Northamptonshire seamer Jack White finished with a five-wicket haul in the innings-and-39-run victory over Essex.
After being put in again still chasing Northamptonshire's first-innings 369, Essex collapsed to 119 all out, with former England captain Sir Alastair Cook dismissed for just six in what could prove to be his last county appearance.
Kent's future in Division One hangs in the balance after Lancashire reached 126 without loss in their second innings to trail by 41 runs.
Joe Denly's 136 had helped Kent to 494, a first-innings lead of 167, but any hopes of a quick victory faded when Luke Wells (69) and Keaton Jennings (52) both made half-centuries before bad light halted play at the Spitfire Ground.
Middlesex's survival hopes are also on a knife edge ahead of the final day of the season after they failed to take the upper hand against Nottinghamshire at Trent Bridge.
Anchored by 140 from opener Ben Slater, along with solid knocks from Joe Clarke (70) and Matt Montgomery (52), Nottinghamshire posted 384 in their first innings in reply to Middlesex's 366.
Off-spinner Josh De Caires finished with 3-56 as Middlesex took maximum bowling points to go with their three for batting.
Kent, though, need only to avoid defeat to finish ahead of Middlesex and stay up.
Warwickshire maintained their hopes of victory over Somerset at Edgbaston after Ed Barnard impressed with bat and ball following another day heavily impacted by the weather.
Somerset finished 90 for two in their second innings - 32 runs ahead - after bowling the home side out for 273.
Josh Davey and Neil Wagner both claimed three wickets, Barnard's patient 73 helped give Warwickshire a first-innings lead of 58 before then taking a couple of wickets himself.
Durham need 10 wickets on the final day against Leicestershire to wrap up their Division Two title-winning season with a victory.
Play eventually got under way after lunch in the afternoon, when Durham managed to claim the remaining four wickets of the Leicestershire first innings for 143. Ben Raine finished with season-best figures of 5-51.
Durham skipper Scott Borthwick enforced the follow-on, but attempts to make inroads into the Leicestershire second innings were blighted by bad light as the visitors finished 13 without loss.
Sussex have third place in their sights after reducing Gloucestershire to 113-5 in their unlikely pursuit of a target of 513 at Hove.
James Coles (128) produced his third century of the season in Sussex's 505 for seven declared and then made inroads into the Gloucestershire top order, taking five wickets before bad light intervened with 14 overs not bowled. Graeme van Buuren was 46 not out.
At Headingley, Yorkshire declared their first innings with a deficit of 127 at tea in a bid to force a season-ending victory against Worcestershire.
The hosts advanced from an overnight 24 without loss to 262-6 in reply to the visitors' 389. George Hill and Matthew Revis both made half-centuries, while Dom Bess finished 48 not out.
Worcestershire then lost a wicket with the first ball of their reply before closing on 18-2, a lead of 145.
At Sophia Gardens, Derbyshire were 68 without loss, a lead of 217 runs, after Glamorgan skipper Kiran Carlson declared at 301-5 after avoiding the follow-on. Alex Thomson took 4-97.
'The players have worked incredibly hard'
Surrey's head coach Gareth Batty spoke to Sky Sports:
"It's strange the news coming halfway through a game. Over a long season to be told it's ours again it's nice, particularly for the players who have worked really hard and the staff who have put in months of work.
"It's the longest race to win, it takes a lot of energy, skill and determination to win. It's a lovely feeling.
"It needs everybody and a commitment from the club because we want to produce England players. It sounds clichéd but it's the group feel and togetherness that helps.
"We'll reminisce about the year and the hard work gone in. We have to let our hair down in these moments, that's what team sport is about."
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