Kent 338 for 1 (Cox 167*, Leaning 110*) lead Sussex 332 (Brown 98) by 6 runs
Teenager Jordan Cox and winter recruit Jack Leaning notched their first centuries for the county as Kent took control of their Bob Willis Trophy south group game. Sussex endured an 85-over day in the Canterbury dirt 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 1 for a narrow six-run lead.
Cox, a 19-year-old right-hander who only opened in this match in the absence of Kent's England duo Joe Denly and Zak Crawley, cruised through the so-called nervous 90s within six deliveries to post his maiden century from 150 balls with 16 fours and a brace of sixes. A Kent Academy product playing only his second first-class innings on the ground, Cox moved to three figures with a huge six over long-on against the bowling of Jack Carson.
The England Under-19 batsman started the Kent response to the Sussex all out total of 332 by featuring in a first-wicket stand worth 107 with Daniel Bell-Drummond. Bell-Drummond fell soon after lunch for 43 when Mitch Claydon, the former Kent seamer, got one to hold its line against the Canterbury slope and graze the shoulder of the bat. Harry Finch completed the dismissal with a sharp low catch at second slip.
Normal service was resumed once Claydon and George Garton rested, however, as Cox combined with Leaning, the ex-Yorkshire batsman and one of four Kent players making their home debuts, to deepen Sussex's woes.
Leaning reached his half-century from 88 balls and with eight fours while at the other end, Cox continued to show excellent judgement of length. Fleet of foot, he skipped down the pitch to drive anything flighted, or rocked back deep into his crease to cut or reverse sweep once the Sussex attack attempted to adjust their lengths.
With his score on 134, Cox took a painful blow in the chest after ducking into a Stuart Meaker bumper but batted on after treatment from Kent physiotherapist Dan George. It proved Cox's sole misjudgement of the day.
Kent reached 200 for their first batting bonus point when, in the 50th over, a Delray Rawlins long-hop allowed Leaning room to cut to the ropes at backward point. The 300 followed in the 74th over when Cox clipped leg side against Garton to reach his own 150 from 221 deliveries.
Leaning, who joined from Yorkshire during the close season, notched his first ton in Kent colours and his fifth in first-class cricket from 162 balls after cutting his 16th four of the day through backward point off a rare loose delivery from Garton.
At the start of day two Kent used up 27 deliveries to winkle out the 10th Sussex batsman. Visiting skipper Ben Brown was the man to go after 283 minutes at the crease and when only two shy of his 19th first-class century. Cutting at one too close to the body from Harry Podmore, Brown chopped the ball onto off stump. Podmore finished with 4 for 85 and rookie offspinner Marcus O'Riordan took career-best figures of 3 for 50.