An off night with the ball and in the field on Friday gave Yorkshire too much to do later in the game as Leicestershire consigned the pre-game leaders to only a second defeat in eight North Group games, by 34 runs with one ball to spare.

The positive was that results elsewhere largely went in the Vikings favour, and they ended joint top with Notts on 11 points from eight games.

Notts had a marginally better net run-rate after a third tie of the competition, against Derbyshire, and sat top.

Having lost the toss, anything which could go wrong seemingly did in the first half of the game for the below par Vikings in good batting conditions.

Only Dom Bess with 0-21 from four overs could reflect on a job well done, with the rest of Yorkshire’s six-man attack going at over 10 runs per over.

Their tormentor in chief was Arron Lilley, the all-rounder who effectively bats as a pinch-hitter at number three in this format.

He clobbered nine fours and four sixes in 55 balls, falling narrowly short of a maiden century.

He shared 75 for the second wicket with Scott Steel (32) from 24-1 in the third over and 90 for the third with captain Colin Ackermann, who made 40.

Yorkshire’s forgettable performance in the field was summed up at the start of the 17th over when Jonny Tattersall failed to hold a Lockie Ferguson slower ball and let it through for four byes.

Ackermann then lofted the next ball high to deep mid-wicket, where Jordan Thompson took a juggling catch only to step on the boundary rope and concede six.

In reply, Adam Lyth’s 22 gave Yorkshire a bright start at 32-0 after three overs, but he and opening partner Tattersall were out to Callum Parkinson in the fourth - caught at point and lbw.

Parkinson later had Joe Root caught at backward point off a full toss for 15 (78-3 in the ninth) and Yorkshire were falling behind the rate.

Ballance played on to Steel’s off-spin for an innings high 34 shortly afterwards and George Hill also fell - 103-5 in the 14th over. Yorkshire still needed 105.

Wednesday’s Worcester heroes Harry Brook and Thompson united, but they weren’t able to turn it around and were removed by Parkinson and seamer Gavin Griffiths as the score fell to 127-7 in the 16th.

And that was all but game up for the Vikings, whose target later became 58 off the last two at 150-8 and then 44 off the last.

Ben Mike claimed two wickets in the last over, including Bess for 24.