Leicestershire's Jim Allenby became the first bowler in Twenty20 history to take four wickets in four balls - but the medium pacer's efforts could not prevent Lancashire from maintaining their 100% start.
Lancashire claimed a 37-run victory over Paul Nixon's team and by the time Allenby performed his last-over heroics - he finished with five for 21 - some explosive hitting by man-of-the-match Kyle Hogg had all but guided the home side to a defendable total of 167 and match-turning figures of four for 21 by leg-spinner Simon Marshall ensured that the Grace Road team would finish well short of their target.
The result leaves Stuart Law's team in prime position to qualify for the quarter-finals and Leicestershire probably needing to win six of their remaining group games to stay in with a chance of appearing in their fifth Twenty20 finals day.
Lou Vincent got Lancashire's innings off to an explosive start when he hooked Garnett Kruger's second ball of the match for six - just as he had done at Grace Road on Wednesday - but the South African soon got his revenge when the New Zealander top-edged a pull and HD Ackerman clung on to the skied catch.
Mal Loye and Stuart Law maintained the Old Trafford side's brisk start with a 43-run partnership for the second wicket in five overs before Law's 10-ball innings of 21 ended when he miscued Dillon du Preez to Kruger at mid-on.
Francois du Plessis played on to Allenby for eight and left-arm spinner Claude Henderson put a brake on the home side's progress with two well-disguised quicker deliveries in the following over to remove Loye for 34 and Gareth Cross for one and leave Law's men struggling on 93 for five.
Hogg, though, showed no signs of being disconcerted by the possibility of a full-blown crisis. The 24-year-old left-hander struck four sixes - three of them off Du Preez - and added 70 in eight overs with Steven Croft to ensure that the Red Rose bowlers had a respectable total to defend on the glued pitch.
Hogg's eventual dismissal for a 24-ball 44 was the start of Allenby's golden over in which he also dismissed Croft, Dominic Cork and Sajid Mahmood but Lancashire's total was 10 more than they had managed at Grace Road and it proved to be sufficient.
The home fans' feelgood factor in a crowd just shy of 8,000 was reinforced when Mahmood removed both Jacques du Toit and Allenby in his first over only for a well-constructed 93-run partnership for the third wicket between Ackerman and Boeta Dippenaar to give visiting supporters grounds for optimism too.
Those hopes were demolished by Marshall who had Dippenaar caught at deep mid-wicket by Vincent before persuading the dangerous Nixon to sky the ball to Loye in the same over, but the Cheshire-born all-rounder's most vital contribution to the contest was to have Ackerman pouched by Law at extra-cover for 63. The task of scoring 62 off the remaining five overs proved far beyond Leicestershire's later batsmen.