Stevens' 44-ball ton chases 337
Kent 337 for 7 (Stevens 118, Northeast 115, Key 52, Beer 3-59) beat Sussex 336 for 5 (Wright 115, Nash 83) by three wickets
Darren Stevens hit the fastest hundred of the county season from 44 balls under the lights at Canterbury to outshine Sussex's Luke Wright and pilot Kent to a remarkable three-wicket win in the Yorkshire Bank 40.
Set to score a mammoth 337 for victory, Kent edged home in a tense finish just before 10.30pm to complete a stunning chase with nine balls to spare. Stevens contributed a blistering 53-ball innings of 118, Rob Key chipped in with 52 and Sam Northeast all but saw them home with a maiden one-day century off 90 balls.
Facing an asking rate of 8.4 an over from the off, Kent made a brisk start to their pursuit as openers Key and Northeast posted 109 inside 13 overs. Soon after reaching a 40-ball 50 with eight fours, Key holed out to long-on against Chris Liddle then, after Northeast's 41-ball 50 with five fours and a six, Alex Blake edged behind with Kent handily placed at 151 for 2 at the mid-point of their reply.
The hosts accelerated as Stevens took 17 off an over from legspinner Will Beer and 20 came off his replacement, Rory Hamilton-Brown. Stevens notched a 24-ball half-century then moved through the gears, scoring his second 50 off only 20 more to match Mark Ealham's 44-ball ton, the fastest ever for Kent, in a 1995 Sunday League clash with Derbyshire.
Stevens hit 10 fours and six sixes and in the process became the front runner for the Walter Lawrence Trophy, awarded for the fastest hundred of the summer. He finally holed out for 118 and marched off to a standing ovation to leave centre stage free for Northeast.
With a modest previous List A best of 69, Northeast plundered 115 with 11 fours and a six but, with only 14 needed for victory, was stumped by Ben Brown when attempting a tired-looking drive against Beer.
Ben Harmison quickly departed leg before and with the tension mounting, Calum Haggett chipped to midwicket and Mitch Claydon was run out for 8, having hit his first ball for six.
It took a leg-side wide from Sussex saint-turned-sinner Wright to clinch Kent's fifth win in eight Group A starts and complete a fourth defeat for the shell-shocked Sharks.
Having earlier been given first use of a sublime St Lawrence pitch, Sussex made the most of a short boundary on the Old Dover Road side of the ground to improve their one-day best total against Kent within 37.2 overs - beating their previous record of 314 for 7, set in the Gillette Cup at Tunbridge Wells in 1963 which, in its inaugural year, was a 65 overs per side competition.
Wright and his opening partner Nash set the ball rolling with an opening stand of 194 in 18.3 overs as Wright plundered 13 fours and five sixes in a 54-ball ton.
He clubbed one more of each before his knock ended on 115 when his edged cut shot against Haggett ballooned off the gloves of Geraint Jones, standing up to the stumps, to be caught at backward point.
Nash and Wright coasted past their county's previous best opening stand of 145 in all one-day cricket against Kent, set by Bill Athey and James Hall and, at 153, beat their record for any wicket in limited-overs cricket against Kent, set here by Wright and Matt Prior in August 2012.
In the process, Wright had beaten Josh Cobb's 62-ball hundred for Leicestershire against Somerset in May to set a short-lived mark for the fastest of the season.
Only 17 short of his hundred, Nash aimed to sweep the occasional left-arm wrist spin of namesake Brendan Nash, only to be caught at backward square-leg. His 83 came off 58 balls with 11 fours and a six. Stevens joined forces with Nash and then Riley to temporarily stem the haemorrhaging of boundaries thereafter and, come the end, the Sussex total somehow proved inadequate.
Michael Yardy (46) perished in pursuit of late runs when he chipped to Stevens as Haggett closed his eight-over stint of 2 for 97 - the most costly one-day bowling figures in Kent's history.