Victory kept Notts four points clear at the top of Group A, but Lancashire joined the chasing pack of Somerset, Surrey and Leicestershire on eight points after backing up Sunday’s win over the Foxes with a six-wicket victory against Kent in Preston.
Put in by the hosts, Kent’s total of 223 after 46.5 overs never looked big enough despite captain Daniel Bell-Drummond (56) leading the way with a half-century.
Lancashire quick Mitchell Stanley did the bulk of the heavy lifting, taking 3-43.
Keaton Jennings continued his decent start to the campaign adding 31 to his opening two scores of 64 against Surrey and 135 against Leicestershire.
Kent struggled to break partnerships as Lancashire put on half-century stands for the second and fourth wickets.
The second of those, 69 runs between Marcus Harris (47) and Rocky Flintoff (41 not out) took them within touching distance of victory.
Flintoff hit the winning runs in partnership with Joseph Moores, nephew of former England coach Peter Moores, as Lancashire won with 13 balls remaining.
Kent remain second bottom of the group with their second defeat in three matches.