Lancashire cruised to a six-wicket win over Yorkshire as they chased down 181-9 to go above their Roses rivals and into third place in the North Group.
David Willey hit 80 from 43 balls for Yorkshire but they lost six wickets and only scored 40 in the last six overs.
Lightning set the groundwork for victory through Alex Davies (34), Karl Brown (51) and Arron Lilley (47).
And they reached 185-4 with little fuss for a win which sends them two points clear of fifth-placed Birmingham Bears.
Elsewhere in the North Group Joe Clarke scored a wonderful 76 as Worcestershire defended a total of 137-8 to beat Derbyshire by 16 runs and return to the top of the table by a point from Durham.
Clarke hit nine fours and three sixes in scoring more than half of his side’s runs, but fellow opener Wayne Parnell (12) was the only other man to reach double figures.
In reply, Billy Godleman top-scored with 38, but Luke Wood, Patrick Brown and Ed Barnard all took two wickets as the Rapids retained control to secure their eighth win in this season’s competition.
Ian Bell inspired Birmingham Bears to a comfortable six-wicket win over holders Notts Outlaws at Edgbaston to move above their opponents, as well as Derbyshire, and up to fifth spot,
Bell, who this week stated his desire to get back into the England Test set-up, scored 54 from 37 balls as his side made light work of surpassing the visitors’ total of 152-4.
Colin de Grandhomme finished unbeaten on 49 as they reached 156-4 with 22 balls to spare.
Cockbain shines as Glos maul Middlesex
In the South Group, Gloucestershire moved up to second place as Ian Cockbain’s magnificent 123 helped them amass 242-4 on their way to an emphatic 70-run win against Middlesex.
Cockbain’s maiden T20 ton came at better than two runs a ball and included ten fours and six sixes.
Middlesex could only manage 172-6 from their 20 overs, with Kieran Noema-Barnett (3-18) dismissing England batsmen Eoin Morgan and Dawid Malan during his miserly spell.
Fifth-placed Surrey’s match against sixth-placed Sussex at the Oval fell victim to a combination of the rain and threat of lightning.
Sussex had made 159-2 from 13 overs when the match was abandoned.