Warwickshire secured their Specsavers County Championship Division One status for another year by completing a thumping 237-run win which left Lancashire sweating on news from elsewhere to learn their survival fate.
Chasing a notional victory target of 347 at Edgbaston, Lancashire were bowled out for 109 early on the final afternoon, their batting pared away by relentlessly accurate bowling led by Rikki Clarke (10.5-3-20-4), Jeetan Patel (24-11-46-3), and Chris Wright (14-8-8-2).
By banking their first home championship win of the season at the last attempt, Warwickshire preserved the First Division status they have held unbroken since 2009.
But Lancashire were left facing a tense wait for tidings from Southampton where victory for Hampshire over Durham would relegate the Red Rose. A draw or Durham victory would reprieve Steven Croft's side.
Lancashire resumed on the final morning on 28 for three, needing to execute a massive rearguard action, and they started in determined fashion as overnight pair Haseeb Hameed and nightwatchman Simon Kerrigan survived for 50 minutes.
But Wright made the vital breakthrough when Hameed (27, 78 balls, four fours) was brilliantly caught by Clarke, low to his left, at second slip.
Clarke then struck with his first ball from the Pavilion End, which Croft bat-padded to Sam Hain at short-leg. When Liam Livingstone edged Patel to Jonathan Trott at second slip, Lancashire were in deep trouble.
Kerrigan showed exactly the sort of resolve his team needed, batting throughout the morning session for ten runs, but his excellent resistance was terminated quickly after lunch. Having made ten from 117 balls (no fours, no sixes) the nightwatchman edged Patel to Clarke at slip.
Clarke then delivered pacy, full-length inswingers to send Jordan Clark's off-stump flying and rattle Tom Bailey's middle and off-stumps to leave Lancashire last pair Arron Lilley and Kyle Jarvis with 58 overs to survive.
Lilley smote Patel for three fours and a six in an over which cost 20 but when Jarvis poked Clarke to Ian Westwood at silly point, Warwickshire's inconsistent season ended on a high and in safety - while Lancashire settled in for that tense wait.
A tense conclusion to the Specsavers County Championship season awaits at Edgbaston where Lancashire will start the final day on 28 for three in pursuit of a target of 347 beat Warwickshire.
Both sides know that defeat would, if Hampshire beat Durham at The Ageas Bowl, send them down to Division Two.
And Lancashire in particular were left hoping from assistance from Paul Collingwood's side after the balance of power tilted strongly Warwickshire's way on the third day in Birmingham as a solid batting effort lifted their second innings to 279 for seven.
Ian Bell's declaration after tea left Lancashire with an awkward 18 overs batting on the third evening and the visitors lost Rob Jones, Luke Procter and Karl Brown. Without a dogged rearguard action, or some assistance from Durham, a Lancashire season which started so strongly could well culminate in the drop.
Warwickshire resumed on the third morning on 12 without loss and soon lost Alex Mellor, lbw to Tom Bailey, but Mellor proved the only batsman in the top nine not to reach 20.
Ian Westwood and Jonathan Trott added 61 in 14 overs before Westwood (34, 79 balls) fell lbw to Jordan Clark's fourth ball of the day. Trott (42, 62 balls), played on to spinner Arron Lilley just before lunch but the clatter of wickets which Lancashire needed to force was prevented by Bell and Sam Hain who added 38.
And after Bell (31, 52 balls) played on to become Kyle Jarvis's 50th championship victim of the season and Hain (30, 36 balls) was lbw to Lilley, further small but significant partnerships were lodged.
Tim Ambrose (59 not out, 114 balls) added 44 with Rikki Clarke (20, 53 balls), 38 with Keith Barker (23, 34 balls) and an unbroken 45 with Jeetan Patel who twice cleared the ropes on the way to an unbeaten 23.
Lancashire's pursuit of 347 started badly when Barker's seventh ball removed Jones courtesy of the 13th lbw dismissal of the match. The 14th followed when Procter offered no shot to Patel and when Brown edged Chris Wright to wicketkeeper Ambrose, the roots of the Red Rose top order had been plucked out.
They desperately need to set more down tomorrow and will look to 19-year-old Haseeb Hameed, who closed on 11 from 49 balls, to play the lead role.
Warwickshire’s Keith Barker took four wickets against the county of his birth to plunge them into danger of relegation on a shortened second day at Edgbaston.
Lancashire enjoyed the best of day one of this Specsavers County Championship battle by bowling their hosts out for 219.
But the Bears, also in danger of the drop, battled back superbly with the ball to bowl the visitors out for 152 and claim a first-innings lead of 67 just before tea today.
If Hampshire beat Durham at the Ageas Bowl, the loser of this match goes down.
A draw here is enough for Lancashire, but that looks unlikely.
Only Steven Croft and Jordan Clark, with 45 and 34, made it to 30 as Barker, overlooked by the Red Rose in his youth, excelled with four for 30 from 20.5 overs to move to 58 wickets for the season.
Warwickshire faced only seven overs in their second innings after tea, reaching 12 without loss, before bad light and rain accounted for the loss of 33 overs.
Lancashire lost four for four in 35 balls to slip from 35 without loss to 39 for four before lunch, including new England opener Haseeb Hameed lbw to Rikki Clarke for 17.
Barker had Luke Procter caught behind in that period, while Chris Wright trapped Rob Jones and Karl Brown lbw.
Croft shared in his side’s two best partnerships of the innings.
He added 40 for the fifth wicket with Liam Livingstone (21) before the latter was caught at short mid-wicket by Barker off Oliver Hannon-Dalby as the score slipped to 79 for five.
The skipper then shared 55 for the sixth with Clark as they reduced the deficit to double figures.
The latter lofted Jeetan Patel’s off-spinners over deep mid-wicket for six sandwiched in between the departures of Croft and Arron Lilley, leaving the score at 145 for seven in the 58th over.
Croft was bowled by Barker, which was the first of five wickets to fall for 18 runs.
Patel bowled Lilley as he advanced down the pitch seemingly trying to match what Clark had done just four balls earlier.
The former New Zealand off-spinner then added his 66th wicker of the season - no one has more in either division of the Championship - when Tom Bailey flicked him to leg slip with 149 on the board in the 62nd over.
Barker then wrapped up the innings with his third and fourth wickets in successive overs.
He bowled Clark in the 63rd as the score slipped to 149 for nine and then removed Kyle Jarvis the same way to force an early tea.
Warwickshire openers then Ian Westwood and Alex Mellor both hit a boundary in six not out apiece.
But a couple of hours lost to weather was a minor boost to Lancashire at the end of a dismal day.
Lancashire's bowlers piled the pressure on Warwickshire on the opening day of their Specsavers County Championship relegation battle at Edgbaston.
With Hampshire making strong progress at The Ageas Bowl, it looks increasingly likely that whichever side loses this match will go down. And Warwickshire are looking vulnerable after they were bowled out for 219, taking just a single batting point.
They are far from out of the game - the ball has swung and there is some assistance for the spinners. But Lancashire completed their solid day's work by reaching 14 without loss at the close and three days after the euphoria of their Royal London Cup triumph at Lord's, Warwickshire's supporters were left anxious by another patchy day's work from their team.
Lancashire owe their ascendancy to bowling of sustained accuracy, led by Tom Bailey (four for 52) and Jordan Clark (three for 20). Only Sam Hain (52, 116 balls, five fours) reached 50 and, as the bowlers maintained the pressure, no partnership got that far.
Lancashire chose to bowl and started perfectly when Ian Westwood was lbw to Bailey's fourth ball.
Alex Mellor and Jonathan Trott added 44 and, after Mellor (27, 40 balls) edged Bailey to first slip, Trott and Ian Bell put on 37. But Clark's dismissal of Trott (25, 87 balls), edging an outswinger just before lunch, set the tone of the day - Lancashire regularly striking just as a partnership seemed to take root.
Having made 83 for three in the first session, Warwickshire made 82 for three in the second. Bell (37, 87 balls) was lbw to Kyle Jarvis, then four balls later came a needless run out. Hain called for a tight single which Tim Ambrose failed to make as Jarvis landed a direct-hit from mid-off.
Hain and Rikki Clarke eked 37 from 15 overs before Clarke was lbw, pulling, to Clark. Hain and Keith Barker defied to add 40, then both fell in the space of ten balls.
Hain's 152-minute resistance ended when Luke Procter won the fourth lbw decision of the innings. Barker was bowled by the impressive Clark.
Jeetan Patel and Chris Wright saw their side to a batting point but Wright feathered an attempted pull at Bailey who rounded off the innings when Patel lofted a catch to deep cover.
Lancashire's young openers Rob Jones and Haseeb Hameed, reached the close unparted, though the latter was dropped on two by Clarke at second slip off Barker.