Lancashire gave their hopes of qualifying for the knockout stages of the Clydesdale Bank 40 a massive boost as they defied both the elements and Middlesex to claim a seven-wicket victory via the Duckworth-Lewis method at Old Trafford.
The wet weather continued to cause mayhem on Monday but Glen Chapple's side dragged themselves back into contention in Group A with their fourth win from six matches after restricting their visitors to 97-8 in a match reduced by rain to 16-overs per side.
Lancashire were then left to chase a further revised target of 97 off 15.
Lancashire's left-arm spinner Stephen Parry starred with career-best figures of 4-21 from four overs before Steven Croft and Karl Brown (36 not out) anchored the chase with a third-wicket stand of 79 in 10 overs.
Croft top-scored with 45 off 34 balls as the hosts moved to joint second with Middlesex on eight points having played one less.
Middlesex's problems began before they had even taken the field when England one-day batsman Eoin Morgan failed to make it to Old Trafford in time for the start of the match after his train had been cancelled.
The left-hander had to take an alternative route via York but Ollie Rayner took his place when the toss was made at 4.20pm.
The match was eventually reduced from a 40-over match to 16 due to numerous rain showers and only opener Dawid Malan adapted to the bowler-friendly conditions for Middlesex as he hit a season's best 48 off 36, including two sixes off Chapple and Ajmal Shahzad.
Shahzad, Tom Smith and Gary Keedy were all amongst the wickets for Lancashire as only two visiting batsmen reached double figures.
Lancashire made a shaky start to their chase by losing Stephen Moore caught at mid-on off Toby Roland-Jones without scoring.
Smith was then brilliantly caught one-handed at mid-wicket by Gareth Berg off the bowling of Steven Crook.
But Croft and Brown batted with caution before putting their foot on the accelerator after further rain accounted for the loss of one over. Both hit sixes over long-on - off Middlesex's Tom Smith and Berg respectively - as the win was secured with 10 balls to spare.