A dramatic collapse by Leinster Lightning late on the second day has given the Northern Knights real hopes of forcing an innings win after another day of complete domination at Waringstown.
Phil Eaglestone, on his home patch at The Lawn, ripped out the Leinster middle order of John Anderson, Simmi Singh, Andrew Poynter and Eddie Richardson as seven wickets fell for just 55 runs.
Left-armer Eaglestone, omitted from the Ireland squads to face Scotland, took his frustration out on the Lightning batsman, who were clearly troubled by his pace, bounce and movement.
Before his introduction the game looked to be meandering towards a tame draw, as Leinster reached 145 for 2, with John Anderson (46) and Ben Ackland sharing a third wicket stand of 87, after Albert van der Merwe (37) and Theo Lawson (1) had fallen in quick succession.
North Down spinner James Cameron-Dow had made the initial breakthrough, trapping Van Der Merwe lbw after an opening stand of 51, and it was he who took a further two wickets near the close, having Tyrone Kane and Max Sorensen caught for ducks.
Ben Ackland was still there at the end, unbeaten on 76 from a marathon 230 balls (7 fours), and it will require an equal feat of patience from he and his Leinster colleagues if the game is to be saved. Leinster finished on 207 for 9, still a mammoth 294 runs in arrears.
Earlier in the day, Nick Larkin had moved from his overnight 200 not out to 247 before skipper Andrew White called a halt to the carnage with the Knights on 501 for 4 declared.
The only wicket to fall was that of James Shannon, lbw to John Mooney for 46.
While Leinster may have already won the Championship title, they will be keen to avoid the ignominy of an innings defeat when play resumes.
It should prove to be an absorbing day in what has been a quite superb season of Inter-Provincial cricket.
