Yorkshire need 68 more runs with seven wickets in hand to secure an opening round Bob Willis Trophy win over Durham at Emirates Riverside.
Matthew Fisher was their star performer thanks to a stunning four-wicket afternoon burst on day three before the White Rose closed on 103-3 from 34 overs in pursuit of a 171 target.
In the early stages of the afternoon, this game was in the balance after a wicketless morning saw former Yorkshire opener Alex Lees move towards an excellent, determined century.
When Lees reached his ton off 253 balls – his fourth in first-class cricket since leaving Emerald Headingley in late 2018 – Durham were 215-3 after 90 overs of their second innings, a lead of 119.
But he was gone for 106 at the end of the next over, sparking a remarkable collapse of six wickets for 18 runs, four of them going to on-song Fisher in 19 balls from the Finchale End.
That left Durham at 239-9, and they were eventually bowled out for 266 to signal tea.
In the evening session, Dawid Malan led the pursuit of a 19-point win on an easing batting pitch with an unbeaten 50, although he was dropped in the slips on 32.
Durham started the day on 106-2, leading by 10.
Lees and South African debutant David Bedingham batted watchfully to advance their third-wicket partnership to 136 – the latter posting 77 – to give the hosts significant hope having been bowled out for 103 in their first innings.
Bedingham was then the first wicket of the day to fall, trapped lbw by captain Steve Patterson – 207-3 after 86 overs, the sixth of the afternoon.
Lees then reached his 16th first-class career century shortly before Fisher took the new ball and steamed in to turn the game back in Yorkshire’s favour.
Prospering with the help of late swing, in to the left-handers and out to the right, the 22-year-old struck four times at a cost of three runs.
He sparked the remarkable collapse as the hosts fell from 221-3.
Fisher uprooted Lees’ off-stump via pad with the sixth ball of the 91st over – the first with the new ball.
In the 95th, the same man then devastatingly yorked Jack Burnham – off and leg-stumps out of the ground – and trapped Ned Eckersley lbw. Burnham was also left sprawling on hands and knees by the ferocity of Fisher’s delivery.
And in the 98th, he then trapped Paul Coughlin lbw.
When Jordan Thompson replaced Fisher after his six-over spell, he also enjoyed success, striking with his third ball of the 103rd over when Ben Raine lost his off-stump.
In the 105th, he left Durham nine down with a lead of 135 when Matty Potts edged him to Tom Kohler-Cadmore at first slip.
Amazingly, Ben Coad went through the innings wicketless. But his contribution was significant having only conceded 23 runs in 25 overs.
Durham’s last pair Gareth Harte and Chris Rushworth then added an important 27 runs to push the target up beyond 170 before the latter was lbw to Patterson (3-62 from 24.2 overs) to end the innings.
Wickets then continued to fall as the White Rose wobbled early in their chase, with Rushworth doing the damage with the new ball.
He had both Adam Lyth and Will Fraine lbw as the score slipped to 4-2 after five overs. At this stage, nine wickets had fallen for 39 runs across two innings.
Kohler-Cadmore (24) and Malan then shared a valuable 52 inside 13 overs before the former departed lbw to Rushworth, who claimed his 500th first-class career wicket.
Malan and Harry Brook (23 not out) then shared an unbroken 47 for the fourth wicket to ensure there was no further damage.
Malan reached 50 off 82 balls in the day’s final over.