Glen Chapple claimed five wickets as Lancashire secured a place in the Clydesdale Bank 40 semi-finals with an 18-run win over Gloucestershire at Bristol.
Evergreen skipper Chapple returned five for 26 as the home side were bowled out for 164 in reply to Lancashire's 182 for nine. That victory left Lancashire certain to finish top of Group A as they boast a three-point lead over second-placed Middlesex, who only have one game remaining.
Things are much tighter in Group C with one point separating top three Sussex, Warwickshire and Kent, all of whom won.
Sussex remained top on 16 points after claiming a dramatic three-wicket win over Yorkshire under the Duckworth-Lewis system at Headingley, while Warwickshire stay one point behind in second place after thrashing Unicorns by 10 wickets at Wormsley.
Level with Warwickshire on 15 points - but with a game in hand on the top two - are Kent, who beat Northamptonshire by five wickets thanks to a stunning half-century by Brendan Nash.
In Group B, Hampshire remained top of the pile with victory over Surrey, but in-form Somerset are hot on their heels. Hampshire won by four wickets in a match that saw England discard Kevin Pietersen out first ball for Surrey playing against his old club at the Ageas Bowl.
Somerset are just two points behind after defeating Scotland by 53 runs under the Duckworth-Lewis system in a rain-affected clash at Uddingston, while Nottinghamshire are a point further back in Group B after defeating Durham by 43 runs at Trent Bridge.
Essex were also among the runs in Group A as they ran up 314 for eight before dismissing Holland for 197 to claim a 117-run victory.
James Foster (79), Tom Westley (59), Ryan ten Doeschate (52) and Owais Shah (44) all contributed for Essex, while India star Harbhajan Singh had Holland in a spin with figures of five for 37.
In Sunday's other game, Leicestershire leapfrogged above Worcestershire off the bottom of Group A with a two-run victory over the fellow strugglers at New Road, with Ned Eckersley the visiting side's hero with an unbeaten 72 from 44 balls that included seven sixes.
- Glen Chapple