A partnership of 162 between Steven Croft and VVS Laxman helped Lancashire hammer Nottinghamshire by nine wickets at Trent Bridge.
The duo's efforts for the second wicket, a new record for the county in the Twenty20 Cup, helped the Lightning overhaul the Outlaws' total of 173-7 with two overs to spare.
Croft finished up unbeaten on 83 from 49 balls having earlier taken 2-35 with the ball. To complete a perfect all-round performance, he also snared two catches in the field.
Not to be overshadowed, Laxman hit eight fours and two sixes to finish 78 not out off 53 balls having lost opening partner Paul Horton for just nine.
Lancashire's efforts with the bat ruined a whirlwind knock of 55 from 32 balls by David Hussey for the hosts.
The Australian, stand-in captain in the absence of Chris Read, smacked four sixes and two fours to give Notts a chance of finishing their campaign with a victory.
Kevin O'Brien - a hero for Ireland in the recent ICC World Twenty20 - made 26 in a 54-run stand with Hussey after Samit Patel had departed for 37.
Sajid Mahmood picked up 2-26 for Lancashire, including the prized scalp of Hussey, who was yorked by the paceman off the final ball of the innings.
The Lightning had already sealed top spot in the North Division and finish the round-robin stage of the tournament with eight wins from 10 games.