Middlesex 313 for 9 (Stirling 125, Morgan 50, Haggett 3-59, Henry 3-60) beat Kent 243 (Kuhn 90, Bell-Drummond 44, Helm 4-49) by 70 runs
Paul Stirling equalled his highest score in the Royal London One-day Cup to set up a Middlesex victory as they overcame Kent by 70 runs at Radlett.
The Ireland international hit a dazzling 125 from 115 deliveries, laying the foundations for his side to post 313 for 9 - and that proved beyond Kent's reach.
Steven Finn, Middlesex'c captain, reacted: ""Stirlo was excellent - the pace at which the ball was coming off his bat was ridiculous at times. We know he's a world-class player in this format, he's proved that on the world stage and we've seen him do that for us."
Despite a spirited knock of 90 from Heino Kuhn, Kent, who have begun the competition with successive defeats, were bowled out for 243 in the 44th over.
For the second match running, Steven Finn won the toss, opted to take first knock and watched as his opening batsmen put together a 50-plus partnership.
Stirling slammed Mitch Claydon for a string of boundaries, while Nick Gubbins looked particularly strong on the off side as he reached 23 before edging Matt Henry behind.
With Darren Stevens bowling a nagging line, the scoring rate dipped and it took a full 11 overs for Stevie Eskinazi to find the boundary.
However, he and Stirling applied themselves and shared a stand of 102 before Joe Denly brought himself on and immediately persuaded Eskinazi to drive to mid-on.
But Eoin Morgan launched two towering sixes off Denly into the car park and kept Stirling company while he progressed to his ton from 99 balls.
Stirling tore into Henry with a burst of 14 from three balls and then smashed a six off Stevens before punching his next delivery straight to mid-off.
That triggered a middle-order wobble, with a further five wickets falling for just 37 runs, three of them to Calum Haggett, who put an untidy opening spell firmly behind him to finish with 3 for 59.
But sensible batting by James Franklin ensured that the home side completed their 50 overs and he dispatched Henry's last three balls for boundaries to lift the total to 313 for 9.
Daniel Bell-Drummond and Zak Crawley made a blistering start to the Kent reply, capitalising on some wayward bowling to accumulate 39 in their first four overs.
But Nathan Sowter's brilliant diving catch at third man off Helm (4-49) removed Crawley and Denly followed for a duck, caught behind off the same bowler.
Bell-Drummond's immaculate timing and appetite to punish the loose ball took him to 44 from 45 deliveries before Franklin had him caught down the leg side.
Kent lost two more quick wickets, but the watchful Kuhn continued to defy Middlesex and built solid partnerships with Adam Rouse and then Haggett.
Haggett clobbered Hilton Cartwright for six, but Cartwright gained his revenge, throwing from mid-on to run him out on an overthrow with 84 still required.
Kent's lingering hopes rested on Kuhn, but the South African chopped on to give Helm his fourth wicket and Sowter finished Kent off soon afterwards with two wickets in three balls.