Kent 384 for 8 (Kuhn 117, Denly 78, Blake 59, T Curran 4-75) beat Surrey 164 (Roy 68, Stevens 6-25) by 220 runs
Kent swept aside neighbours Surrey by 220 runs to land a fourth successive Royal London One-day Cup victory with almost 20 overs in hand on a flat pitch in Beckenham.
Heino Kuhn's century helped Kent post 384 for 8 - their best List A score against a first-class county - then Kent fielded tigerishly in support of Darren Stevens' career-best 6 for 25 as Surrey succumbed for 164 inside 30.1 overs.
Chasing at 7.7 an over, the visitors lost deposed England opener Mark Stoneman when he dabbled outside off against Matt Henry to be caught behind, then Sam Billings pouched another as Will Jacks nicked an ambitious back-foot force against Mitch Claydon.
Though he needed treatment for a bruised right thumb early on, Jason Roy eased to a 39-ball 50, but might have gone run out for 52 when Sean Dickson missed with a direct hit from backward point.
Left-arm spinner Imran Qayyum, on his season's debut, teamed up with Calum Haggett to send down a string of tight overs that forced Roy to try and break the shackles only to chip to long-off and exit for 68.
Qayyum struck again, holding a sharp overhead return catch to account for Ben Foakes then, with the run-rate edging past nine an over, Stevens clipped Ollie Pope's off stump as the right-hander aimed to push-drive.
Stevens snared Rikki Clarke leg before with an off-cutter, had Rory Burns held at mid-on for 42, rearranged Tom Curran's stumps and trapped Jade Dernbach lbw for his third career List A five-for before taking his sixth wicket in 29 balls by having Gareth Batty caught in the deep.
Batting first after losing the toss, Kent equalled their highest total in List A cricket and their best against Surrey, easily beating their 337 for 3 at Canterbury a decade ago.
Openers Kuhn and Daniel Bell-Drummond laid the foundations in notching 55 in the 10-over Powerplay though Kuhn was dropped on 21 when Dernbach downed a low return chance.
Bell-Drummond lifted the 3,000-strong crowd with the first six of the day, clearing the left leg to a Curran free-hit, he easily beat the ropes over long off as he and Kuhn added 93 before Bell-Drummond slashed at a Curran wide to be caught behind.
Kuhn reached his second half-century of the campaign from 58-balls and, in the process went past the 4,000-run milestone in List A cricket as he and Joe Denly kept the board ticking at a run-a-ball.
Denly broke loose with a flat, straight six off Batty to raise his 45-ball 50 as Kent reached 156 for 1 at the innings mid-point, but, with his score on 78 from 71 balls, Denly smashed a Curran long-hop to wide mid-on to end a second wicket stand of 138 inside 19 overs.
Kuhn posted his maiden List A century for Kent from 91 balls with 10 fours and a six, yet soon lost skipper Billings when, in looking to glance, he gloved to the keeper and gifted Clarke a wicket.
Alex Blake plundered four successive sixes off Batty to raise Kent's 300 and his own 50 from 24 balls. In looking to clear the ropes again, Blake skied to Roy at long off to go for 59.
Kuhn, who cramped up toward the end of his 193-minute stay, departed for 117 after top-edging a hook to long leg against countryman Morne Morkel, then Dickson, in attempting to reverse paddle, was bowled by Dernbach.
Cameos from Stevens and Haggett helped Kent equal their List A record total against Berkshire at Finchampstead in 1994, while, of Surrey's bowlers, only Curran with a flattering 4 for 75, will want to remember the day.