Worcestershire Seconds were unable to capitalise on a promising start after being put into bat by Yorkshire Seconds on the opening day of the Second Eleven Championship match at York CC.
The visitors reached 101-1 with Joe Clarke and Ross Whiteley, the century-maker in the Trophy clash between the sides, looking in control.
But the last nine wickets went down for 52 runs and, after Graeme Cessford and Whiteley each picked up a wcket, Yorkshire reached 135-2 by the close.
Worcestershire openers Matt Pardoe and Clarke put on 38 and then Whiteley and Clarke added a further 63.
But, when Whiteley was bowled for 30 in the 27th over, it started a collapse in which three wickets fell for six runs in two overs including Clarke who was caught behind for 47.
Ed Barnard and captain Gareth Andrew steadied the boat to take Worcs to 116-4 at lunch.
Barnard was caught behind five balls after lunch and Andrew was run out six balls later to leave Worcestershire on 117-6.
The last four wickets fell for 36 runs despite a 16 run stand for the last wicket between Ben Twohig and Cessford.
Andrew Hodd started positively for Yorkshire, scoring 24 off 36 balls before being bowled by Cessford in the 11th over.
Mosun Hussain had just four runs at this point and continued in the same slow vein until he was lbw to Whiteley for 14 off 51 balls in the 18th over with Yorkshire 48-2 at this stage.
Dan Hodgson and Jack Leaning batted sensibly throughout the rest of the day.
Yorkshire have only been scoring at 2.6 an over and needed longer (36.5 overs) to reach 100 than Worcestershire (26 overs).
Worcestershire first innings: Pardoe c Leaning b Wainman 18, Clarke c Hodgson b Coad 47, Whiteley b Shaw 30, D'Oliveira c Leaning b Shaw 2, Barnard c Hodgson b Wainman 5, Andrew run out 4, Hepburn b Wainman 5, Rhodes c Hodgson b Fisher 9, Twohig c Gibson b Coad 13, Harrison b Fisher 0, Cessford not out 4. Total 153 all out (49.3 overs).
Bowling: Coad 2-25, Wainman 3-45, Fisher 2-26, Shaw 2-15.
FOW: 38, 101, 103, 107, 116, 117, 131, 137, 137, 153.
Yorkshire first innings: Hodd b Cessford 24, Hussain lbw Whiteley 14, Leaning not out 50, Hodgson not out 29. Extras 10. Total 135-2 (52 overs).
Bowling: Cessford 13-3-43-1, Whiles 12-5-23-0, Whiteley 8-2-13-1, Harrison 7-3-18-0, Twohig 6-0-16-0, Barnard 4-0-9-0, D'Oliveira 2-1-2-0.
FOW: 32, 48.