Paul Stirling hit a superb unbeaten 132 off 96 balls as Middlesex Panthers ended Leicestershire Foxes' 100 per cent record in the Yorkshire Bank 40 with a crushing 10-wicket win at Grace Road.
The Foxes were bowled out for 220 and Stirling, dropped before he had scored, made them pay by sharing a unbeaten opening stand of 221 with Dawid Malan as Middlesex raced to victory with 9.4 overs to spare.
Stirling struck the winning runs with his 19th boundary and Malan finished on 80 not out off 86 balls with a six and seven fours.
It was a record opening partnership for Middlesex in limited-overs cricket, beating the previous best of 218 against Gloucestershire Gladiators last season between Malan and Chris Rogers.
Stirling was put down at slip by Greg Smith off Anthony Ireland in the second over, and celebrated by hitting the next three balls to the boundary.
He reached 50 off 29 deliveries and his century came up off 71. Malan gave him great support in a chanceless knock as the Foxes attack was put to the sword.
It was a disappointing batting performance from Leicestershire, with several players getting starts without going on to make a telling score.
Yet they looked on course to post a competitive total when they were 102 for one in the 16th over. Then five wickets fell for 36 runs in 11 overs and, from that point on, it was an uphill battle for the hosts.
Josh Cobb, having scored three consecutive centuries in the competition, hit the first ball of the Group C match to the boundary and made 25 in an opening partnership of 51 with Niall O'Brien, before being bowled by James Harris.
O'Brien and Smith also shared a second-wicket stand of 51 with the latter hitting a massive straight six off Tim Murtagh. But when Smith was caught behind by wicketkeeper Adam Rossington off Murtagh for 30, his departure triggered a collapse.
O'Brien was caught at point for 41 off 46 balls, Joe Burns edged to slip without scoring before Shiv Thakor and Matthew Boyce were both snared by off-spinner Ollie Rayner as the Foxes slipped to 138 for six.
Michael Thornely, with 39 off 40 balls, helped to rebuild the innings and take the total past 200, but Jigar Naik was last man out with one ball left.
It was the Leicestershire’s first defeat in four games and Middlesex's second win in five.