But the visitors secured a Blast quarter-final berth with an impressive 11-run win over the North Group leaders at Old Trafford.
Lightning failed to chase 16 off the last over from ex-West Indies quick Ravi Rampaul (three for 19 from four overs).
Liam Livingstone’s 58 off 36 balls was the feature of Lancashire’s 151 for nine in front of 14,752 crowd – a non-Roses Blast record at Old Trafford.
Wayne Madsen top-scored with a superb 69 off 39 balls, while captain Billy Godleman ably supported him with 57 off 50 as Derbyshire posted 162 for three.
The second-wicket pair shared 112 inside 13 overs to advance from 17 for one in the fourth having elected to bat.
Derbyshire’s total could have been even higher.
Godleman and Madsen were excellent, the latter in particular as he mixed power with invention and hit six fours and three leg-side sixes.
Godleman, meanwhile, moved to the 940-run mark in both forms of limited overs cricket this season. No one else in county cricket has been as prolific.
Madsen reached 50 off 27 balls before left-handed Godleman followed him to the same milestone off 45 balls.
With those two together, Derbyshire were ideally placed at 96 for one after 12 overs. But they only scored a further 66 runs from the last eight.
Three of the last eight overs were, however, bowled by the miserly Australian left-arm seamer James Faulkner.
Meanwhile, Lancashire bowler Stephen Parry has been awarded a testimonial year in 2020 after signing a new one-year deal with the county.
The long-serving left-arm spinner, who came through Lancashire Cricket’s Academy, will extend his stay until at least the end of next summer.
Parry has appeared in 230 matches for the Red Rose since making his debut back in 2007, and is the club’s all-time T20 leading wicket-taker with 117 scalps, more than 45 wickets ahead of fellow left-arm spinner Gary Keedy.
He has appeared in 116 T20 matches to date, second to only Steven Croft in Lancashire’s all-time appearances in the format.
Parry said: “It has been an honour to play for the club and I am truly grateful for being given a testimonial. To be recognised in this way is very special.
“To have spent my whole career at this great club, and to have been awarded a testimonial, is something that I will cherish forever.
“I am also pleased to have extended my contract for another season.
“I love pulling on the Red Rose and I look forward to contributing to the side for another year.”