Yorkshire 155 and 113 for 1 (Lyth 51*) lead Leicestershire 223 (Swindells 73, Hill 4-63) by 35 runs
Harry Swindells, the unlikely hero as Leicestershire picked up their first silverware in 12 years last weekend, kept alive their hopes of a return to Division One in the LV= Insurance County Championship for the first time in 20 years on day three against Yorkshire at Grace Road.
Fresh from his match-winning 117 not out in Saturday's Metro Bank One-Day Cup final - his first List A game of the season - Swindells top-scored with 73 in his first appearance of the year in the Foxes' red-ball team to secure a potentially valuable lead in this rain-affected match, albeit one that Yorkshire have chalked off for the loss of one wicket.
Swindells shared a 10th-wicket partnership of 93 with Will Davis, who added a career-best unbeaten 44 to his 4 for 28 with the ball, as Leicestershire recovered from 140 for 9 to be bowled out for 233 in reply to Yorkshire's 155. They had earlier been teetering at 97 for 6 as Yorkshire seamer George Hill took 4 for 69.
Openers Adam Lyth and Finlay Bean continued their prolific form with their fourth 100-plus partnership of the season as Yorkshire closed 35 runs in front on 113 for 1, Bean having been bowled by Tom Scriven offering no shot. Rain and bad light cost a further 25 overs on the day.
Leicestershire have two matches in which to overturn a deficit of 21 points behind second-placed Worcestershire if they are to join already-promoted Durham in Division One next season. A win in this match would be worth 19 points.
Frustrated by bad light on the first evening and a complete washout on day two, it took Leicestershire only three deliveries on the third morning to snare the last Yorkshire wicket, Ben Cox taking a smart one-handed catch as Scriven dismissed Jordan Thompson to finish with 3 for 27.
Yet until Swindells and Davis came together, Leicestershire looked to have wasted an opportunity to put themselves in a dominant position.
On a pitch that looked no picnic to bat on, at least in the early part of the day, the home side suffered a setback two balls into their reply when Rishi Patel was given out leg before to Ben Coad despite getting forward a couple of good paces, but skipper Lewis Hill seemed determined that Coad and new-ball partner Thompson would not be calling the shots.
Hill rattled off eight boundaries in the next nine overs as he and Sam Evans added 57 for the second wicket. But after his namesake George replaced Coad in the first change, Yorkshire seized the initiative.
The former England Under-19 seamer's first over conceded three of those eight boundaries, albeit one off a streaky inside edge, but he had the right-hander caught behind pushing at one in the next over and his dismissal prompted a Leicestershire collapse.
From 58 for 1, they were 97 for 6 by lunch. Sam Evans and Umar Amin were leg before to Hill, the latter more convincingly than the former, before Bean caught Louis Kimber at third slip via second slip Lyth's chest as 20-year-old Ben Cliff struck with the fourth ball of his second first-class match. In the last over of the session, Cox became the fourth batter to see umpire Neil Pratt's finger raised as Hill claimed his fourth wicket.
Scriven, on 2, was dropped twice off consecutive Coad deliveries soon after lunch, both put down by Lyth at second slip. He and Swindells appeared to steady the ship, only for three wickets in the space of seven balls to threaten to hand Yorkshire a first-innings lead. Lyth held a much more difficult catch to dismiss Scriven off Thompson, who sent Chris Wright's off stump into a cartwheel two balls later before Cliff bowled Scott Currie.
Yet it turned out Swindells was in the mood for more heroic deeds, leading an equally assertive Davis in a record 10th wicket stand for Leicestershire against Yorkshire, beating the mark of 70 set by George Geary and Alec Skelton in 1927, when the counties met at Leicestershire's original home ground in Aylestone Road.
Picking up most of his runs square of the wicket, Swindells completed a 57-ball half century containing seven fours. Davis hit seven boundaries to pass his previous best of 42 against Kent here two years ago before Swindells feathered a catch behind off Matthew Revis, with a useful 78-run lead in the bank.
Both Davis and Swindells are out of contract at the end of the season and have yet to learn if they will be offered new ones.