Leicestershire 147 for 8 (Kelly 44, Hasan 4-18) beat Yorkshire 135 (Bairstow 39, Rehan 3-28) by 12 runs
Leicestershire Foxes recorded their first home win in any format this season at the fifth attempt as they beat Yorkshire, unchanged for a fourth successive match, by 12 runs at Grace Road.
Yorkshire remain clear at the head of the Vitality Blast North Group, but, needing 48 from 44 balls at 100 for 3 they lost their seven wickets for 35, three of them to Rehan Ahmed's legbreaks in 13 balls.
Put in, the Foxes had themselves declined earlier from 90 for 2 to 96 for 6 before posting 147 for 8 with 44 from New Zealand's Nick Kelly, as superb bowling from Pakistan international Hassan Ali brought him his first four-wicket bag since joining Yorkshire this campaign.
Needing 7.4 per over, Yorkshire captain Jonny Bairstow, opening, belted 39 from 21 balls and Will Luxton stroked a fluent 38 but was first to go in the final catastrophic plummet to 135 when the final wicket fell to the penultimate ball.
Bairstow, who came into the game as the second-highest run-scorer in this summer's competition, set what looked like being a winning tone by hammering 14 off the reply's first over but in the fifth both he and partner Adam Lyth fell in Ian Holland's first five balls.
After nine overs, Leicestershire had been 75 for 2 and Yorkshire were 72 for 2 but an out-of touch James Wharton was bowled next ball for two off ten attempting a ramp.
Luxton then fell LBW to Rehan and Moeen Ali was run out - by Rehan and wicketkeeper Ben Cox, turning for a third - in the next over before Matt Revis went for five. With six men gone, 35 were soon needed from the final four overs. But batters continued to depart after 13 balls' respite and 27 from the final 20 proved beyond them.
Earlier, the Foxes faltered at the start when Rehan, released from England Lions duty, skipped out to Hassan but swiped to mid-on for a second-ball duck in the opening over. Two overs later, new batter Kelly escaped a chance in the deep off Faheem Ashraf when two.
By the end of the powerplay after six overs, though, they were 46 for 2 and Yorkshire were already regretting their reprieve when Kelly claimed his first six next over before Jonny Tattersall, meeting his old team-mates for the first time, also escaped, on six when Wharton lost his footing on the mid-wicket boundary.
A superb over, the 11th, from Hassan, conceding only a single, finally put paid to Kelly, however, and it suddenly became four out in 15 balls when Ashton Turner came and went without score, Tattersall (also bowled) fell for 29 and Ben Green gave Jafer Chohan a second wicket, LBW for one.
Ben Cox passed 3000 T20 runs, finishing unbeaten with 33 in helping 47 to come from the last six overs, but the Foxes looked just short of par. Improbably, however, the undefeated Cox was, in retrospect, a match-winner.
