Teenager Jordan Cox and winter recruit Jack Leaning notched their first centuries for Kent as the home side took control of their Bob Willis Trophy south group game against Delray Rawlins and his Sussex teammates.
Sussex endured an 85-over day in the Canterbury dirt for only one wicket as Kent’s second-wicket pair piled on a record unbroken stand worth 231 - beating the club’s previous best against Sussex of 229, set by Kentish legends Arthur Fagg and Leslie Ames at Hastings in 1948.
By stumps and the midpoint of the match, Cox had reached a career-best 167 not out while Leaning finished unbeaten on 110 as Kent closed on 338 for one for a narrow six-run lead over their neighbors from Hove.
Rawlins finished the day with figures of 10-0-34-0.
