Yorkshire 36 for 2 trail Leicestershire 124 (Coad 5-18) by 88 runs
Ben Coad claimed a superb 5 for 18 as Leicestershire were bowled out for 124 before tea during a seamer-friendly opening day of the Bob Willis Trophy clash at Emerald Headingley.
The 26-year-old excelled with the new ball and returned after lunch for further success as Yorkshire made an encouraging start to their bid for a victory which could see them advance to the five-day Lord's final later this month.
They realistically need to win to topple leaders Derbyshire and finish top of the North Group. Then, they must finish as one of the two best group winners from the North, South and Central.
Rain again played its part for the third successive four-day game on this ground, with Yorkshire closing on 36 for 2 from 12.1 overs of their reply. There was no play beyond 4pm and 28.5 overs lost.
Second-placed Yorkshire know that if Derbyshire, who led the North Group by five points before the final round, beat Lancashire at Liverpool and accrue 20 points, there is nothing they can do.
But for now, they will celebrate a highly impressive bowling display led by Coad, whose first wicket of Sam Evans was his 150th in first-class cricket in his 38th appearance.
This is only his second game of the summer having suffered a torn oblique muscle in the opening round victory at Durham last month. It is the same situation for new ball partner Matthew Fisher (abdominal), who chipped in with 3 for 29 from 12 overs as swing and seam dominated under overcast Headingley skies.
Stand-in captain Adam Lyth won the toss and elected to bowl. Lyth was captaining Yorkshire in place of Steve Patterson, who has been ruled out having suffered back spasms in the couple of days leading up to this fixture.
Leicestershire, playing only for pride, slipped to 12 for 3 and 36 for 4 before reaching lunch on 52 for 4. Fisher claimed two of the first four wickets, while Coad and Duanne Olivier also struck.
Fisher had Hassan Azad and Colin Ackermann lbw, while Coad also pinned Azad's opening partner Sam Evans lbw. Olivier's wicket came courtesy of a brilliant one-handed return catch to get rid of Harry Dearden.
Four of Coad's first six overs were maidens, and he continued to give Leicestershire's batsmen nothing after lunch and got more rewards as a result. Coad had Rishi Patel caught at second slip by Lyth. He then trapped Arron Lilley lbw and wrapped up the innings by getting wicketkeeper Harry Swindells caught behind by Jonny Tattersall and Alex Evans caught by Lyth, the latter two in successive balls.
In between, Fisher had Ben Mike caught at third slip by Harry Brook, who also held on in the same position as Olivier got fellow South African Dieter Klein.
Swindells offered Leicestershire's only significant resistance with a polished 36, including three successive fours in one Olivier over.
But they were given a significant boost inside the first three overs of the Yorkshire reply after tea, with Alex Evans and Klein removing Tom Kohler-Cadmore and Lyth as Yorkshire slipped to 4 for 2. Kohler-Cadmore was caught at square-leg by Sam Evans and Lyth edged behind to Swindells.
Will Fraine and Tom Loten steadied the ship before rain forced the players off the field and brought a premature end to an absorbing day's play. Umpires Peter Hartley and James Middlebrook abandoned the day at 5.20pm.