Lancashire's relegation to the Second Division only a year after winning the County Championship was confirmed when they were beaten by 109 runs by Middlesex at Lord's after Surrey had bowled out Nottinghamshire for 151 to win by 195 runs at The Oval.
Glen Chapple's side needed at least to match Surrey's result to keep their season alive ahead of their meeting with Surrey at Liverpool next week but Middlesex set them a stiff target of 304 to win from 39 overs, by which time Surrey had already triumphed.
It meant Lancashire could not contemplate settling for a draw and the scoring rate required inevitably cost them wickets. The Australian-born seamer Steven Crook took a career-best 5 for 48 including three wickets in one over as Lancashire's hopes disintegrated. They were dismissed for 194 in just 32 overs.
Chapple himself had finished with 5 for 47, denying Dawid Malan a century when he had him caught behind for 95, before Middlesex declared. It gave the veteran seamer 10 wickets in a match for the third time in his career but while he cut a dejected figure when Simon Kerrigan was last man out, he denied that he was retiring, even though he will be 39 in January.
Lancashire have won only one match in their title defence and are relegated along with Worcestershire. Middlesex leap into second place, which would be worth £235,000 in prize money should they stay there, although they have completed their fixtures.
Somerset, who pulled off an astonishing win when they chased down 396 to beat Sussex at Hove, are third, with Sussex fourth and Nottinghamshire fifth, all of whom have one match left and a chance of taking the runners-up prize. Third place is worth £115,000 with £35,000 to the side finishing fourth.
James Hildreth, who finished unbeaten on 101, and Peter Trego secured Somerset's win by scoring 166 in just 25.3 overs, Trego smashing 89 off 72 balls.
The real drama of the final week will be played out in the Second Division after defeat for leaders Derbyshire against Kent set up a three-way race for the two promotion places involving those two sides and Yorkshire.
Hampshire effectively dropped out of the race when they lost by 122 runs to Essex at Southampton despite Jimmy Adams, carrying his bat for 139 not out.
Kent's resounding win at Canterbury, where Derbyshire collapsed from 103 for 3 to 181 all out, means that only six points coves the first three in the table.