Set a target of 443 to win from 135 overs after Nottinghamshire had declared their second innings on 339 for eight seven overs before tea, they were 115 for one from 39 overs at the end of the third day after Luke Wells (57) and George Balderson (45) shared an unbroken stand of 110.
Earlier, Tom Moores (97) and Lyndon James (91) each just missed out on hundreds but put Nottinghamshire in what looked like a strong position with a partnership of 176 for the sixth wicket, yet their bowlers have found little encouragement from an increasingly benign pitch.
Luke Fletcher, the country’s leading wicket-taker, struck with his fifth ball as Lancashire began their chase, a misjudgement from Alex Davies giving him his 57th success of the season and the 400th of his career in first-class games as the opener shaped to leave a delivery that clipped his back pad.
It will still take a history-making effort to get Lancashire over the line. The Red Rose county have scored more runs in the last innings only once and never to win a match. The county record for a successful fourth innings chase is 404, set in 1910.
The stakes are high for both sides in this four-match mini series to decide the 2021 title. The winner of this match, assuming there is one, will top the table at the halfway stage if Warwickshire fail to beat Hampshire at Edgbaston, or at least stay in close contention.
Earlier, Lancashire were hopeful of giving themselves a much easier task after Nottinghamshire resumed at 127 for five, just 231 runs in front.
But their overworked seam bowlers, charged with covering for the injured Saqib Mahmood, could not create even a chance, let alone take a wicket, as James and Moores added 103 before lunch and another 53 thereafter.
Ultimately a century eluded both in turn as they each fell to Wells’s leg spin. Moores, who scored 72 in boundaries, was three away from a third first-class century when he slogged to deep midwicket; James, having passed his previous best of 79, was on 91 when he was caught at mid-off, having hit 13 fours.
Tom Bailey, returning to bowl off-breaks with a ball that was 106 overs old, took a wicket second ball as Brett Hutton skied to long on but after Liam Patterson-White had rushed to 37 from 35 balls, skipper Steven Mullaney called his batters in.
Meanwhile, Nottinghamshire are making no comment about stories linking head coach Peter Moores with a return to international cricket as successor to Misbah-ul-Haq, who stepped down as Pakistan head coach on Monday.
Moores, who has twice been England coach, turned down an offer from the Pakistan board in May 2016, when he was working as a consultant at Trent Bridge, saying it was “not the right time for me or my family.”
He became Nottinghamshire’s head coach in September of the same year and his current contract, agreed in 2019, expires after this season.
He is bidding to become the first coach to win the County Championship with three different counties, having previously led Sussex (twice) and Lancashire to the title.