Whatever develops in the remaining two days of this absorbing, low-scoring contest, it is going to be harsh for either Ian Blackwell or Gary Keedy to end on the losing side. The left-arm spinners have skilfully exploited a bone-dry pitch that has offered sharp turn from the start, returning combined figures of 12 for 146 in a pair of first innings that lasted only four full sessions.
Blackwell, the burly 32-year-old from Chesterfield who had previously struggled to repeat the impact he made in helping Durham to retain the Championship title after joining them from Somerset last year, followed season's best figures of five for 78 with a precious half century that went a long way to securing his side's first-innings lead.
But his dismissal by Keedy underlined the tough test that the champions may yet face batting last, especially if Lancashire, currently 34 behind, can set a target of at least 150. After racing to 50 from 40 balls, Blackwell had decelerated to 65 from 67 in a disciplined fifth-wicket stand of 45 with his fellow left-hander Ben Stokes when he shouldered arms to a ball that pitched well over a foot wide, but spun viciously out of the bowlers' footmarks to rock back the off stump.
Phil Mustard fell sweeping at Keedy two balls later, and when Luke Sutton took an acrobatic catch to collect Stokes' top-edged sweep, Durham had slumped from a commanding 169 for four to a precarious 175 for seven. But another intelligent partnership of 51 between Scott Borthwick and Liam Plunkett steered them into the lead before Keedy rattled through the last three wickets in the space of four overs to complete figures of seven for 68, the best of the Yorkshireman's long career west of the Pennines.
That left Lancashire with 11 overs to bat until the close, a period they desperately needed their openers to survive. But Paul Horton was caught behind flicking loosely down the leg-side at Mitch Claydon, and Steve Harmison was simply too good for Tom Smith, who edged to second slip.
That was the 18th wicket to fall for 301 on a day that had started with Harmison taking three for 17 in a high-class nine-over spell. Championship cricket does not come much better.