Yorkshire are on course to win their first home Roses match since 2001 and only their second in 25 seasons after setting Lancashire a stiff target of 349 on the third day of the Specsavers County Championship match at Headingley.
The Championship front-runners had reached 41 for one when bad light stopped play which left them requiring a further 308 runs in a game which has so far seen only one century partnership.
Yorkshire had to fight hard to impose their authority on a contest of many twists and turns and they were still breathing uneasily at 89 for six when their lead was a modest 201.
Tim Bresnan and Adil Rashid brought some stability to the situation with a 41 stand but it was not until Rashid was joined by Liam Plunkett that Yorkshire fans could start to relax under the floodlights which had been switched on for all but the first 40 minutes.
With Rashid playing wristy strokes and Plunkett driving powerfully, the eighth-wicket pair added 74 together before Simon Kerrigan had Rashid caught by stand-in wicket-keeper Steven Croft, scrambling to short leg to hold the bat-pad chance.
There was no stopping Plunkett, however, as he approached his half-century and, after getting there with a boundary off Kerrigan, he drove the left-arm spinner into the boards at the back of the north-east stand. But in attempting another big hit in the same over he was caught by Alviro Petersen at long-off for 57 from 84 balls with seven fours and a six.
Lancashire were handicapped through being without paceman Tom Bailey, who had not re-appeared after injuring his side in the first innings, but they were outstanding in the field and their sharpness denied Yorkshire quite a few runs - particularly when the pressure was on.
Starting the day on 77 for three, Yorkshire were soon finding it difficult, mainly against Neil Wagner who ended with four for 71 - his second four-wicket haul of the match - leaving him with 28 wickets this season to join colleague Kyle Jarvis as the leading wicket-takers in the First Division.
Adam Lyth, after striking Wagner’s first ball of the morning for four, then had his leg-stump uprooted with the next, and after nightwatchman Steve Patterson had survived 10 overs for a single, he edged Tom Smith to Croft.
Skipper Andrew Gale’s run of indifferent form continued as Wagner had him caught at short leg but - not for the first time - Yorkshire were rescued by the second half of the batting order.
Lancashire openers Smith and Haseeb Hameed survived together for 13 overs before Smith drove Patterson gently to Plunkett at short cover, leaving Luke Procter to keep Hameed company until bad light ended play with 16.4 overs remaining.