Surrey secured their Division One status for another season after completing a 195-run win over Nottinghamshire in their penultimate game.
Set a target of 347 on the final day at The Oval, Nottinghamshire collapsed to 151 all out in 64.5 overs with eight of the wickets falling to spin.
Surrey skipper Gareth Batty led the way with 4-30 and there were two apiece for Murali Kartik (2-21), who took the new ball, and Kevin Pietersen (2-24).
Opener Neil Edwards' 31 was the top score for the visitors, who suffered their second defeat of the season.
Surrey picked up 21 points for their efforts, a haul that left Lancashire in real trouble. The Red Rose county proved unable to chase down a target of 304 against Middlesex, meaning they will join Worcestershire in Division Two.
Zander de Bruyn and Gary Wilson struck half-centuries for the second time in the match to help Surrey set Nottinghamshire a victory target of 347 on the final day of their LV= County Championship Division One clash at the Oval.
With seven of the 10 wickets to fall on day three being shared by the spin duo of Graeme White (4-97) and Sam Wood (3-64), the stage would now appear to be set for Murali Kartik and Gareth Batty to spin the hosts to victory.
Surrey, who began the third day with a first innings lead of 42, were indebted to De Bruyn (78) and Wilson (57), who shared a century partnership in the first innings, as they registered 304 all out second time around.
Kevin Pietersen was once again undone by left-arm spin, White luring the England man into a big shot which ended with Ben Phillips pouching a catch at long off.
Jason Roy mixed vigilance with calculated aggression to make 41 off 50 balls before handing Wood his maiden first-class victim, while De Bruyn and Wilson added 90 for the sixth wicket to keep Notts at bay.
Notts, who can no longer win the title following Warwickshire's victory over Worcestershire, opened with nightwatchman Harry Gurney, who played out a maiden before the close.
Tim Linley took 5- 62 to help give Surrey a first-innings lead of 42 over Nottinghamshire on day two at the Oval.
But for Chris Read's unbeaten 85 Nottinghamshire, who could only muster 227 in reply to their hosts' 269, would be out of contention.
Read - who batted for four hours, faced 186 balls and hit a six and eight fours - found a lone ally in 19-year-old Sam Wood (45) as the trio of Linley, Murali Kartik and Stuart Meaker shared the spoils.
Meaker did the early damage, accounting for Riki Wessels (5) before relieving Adam Voges (2) of his off stump, with Linley sending Alex Hales and James Taylor back and Kartik removing Steven Mullaney to leave Nottinghamshire on 60-5 after just 25.1 overs.
Read steadied things putting on 92-run in 30 overs with Sam Wood, the latter making it to 45 before he guided Kartik into the hands of Rory Burns at forward short leg.
Read moved to a 143-ball half-century with his fifth four, which disappeared through extra cover, but wickets continued to fall at the other end until he finally ran out of partners.
Nottinghamshire reduced Surrey to 242-9 on the opening day of a Division One fixture which could still have implications at either end of the table.
Surrey, the only team seemingly still able to be dragged into a relegation scrap, were struggling to reach a second batting point at the end of the first day at The Oval.
Zander de Bruyn made 71 and Gary Wilson 68 but Ben Phillips (3-44) and Harry Gurney (3-47) took three wickets apiece to check the hosts' progress.
Kevin Pietersen, fresh from a century at Taunton last time out, made just 15 before edging left-arm seamer Gurney through to Chris Read.
Tail-enders Stuart Meaker and Tim Linley will be tasked with adding eight more runs to their stand of 11 on day two to lift the Brown Caps a point further clear at the foot of the table.
Surrey began the day 17 ahead of Lancashire, with bottom-placed Worcestershire a point further back.