Surrey 17 for 1 trail Kent 282 (Key 89, Northeast 73, Curran 3-64) by 265
Rob Key hit 89 on his return to County Championship action but Surrey emerged with the opening day honours at a redeveloped Beckenham as Kent's first innings fell away sharply to 282 all out amid a rash of poor strokes. In reply Surrey were 17 for 1 at stumps, having lost Zafar Ansari leg-before to Matt Coles for 3 in eight awkward overs before the close.
Key added 133 in 28 overs with Sam Northeast, who made a fluent 73, but from 182 for 2 Kent let things slip badly on a good pitch after three wickets went down for just seven runs in mid-afternoon. Sam Billings, Fabian Cowdrey and Coles did offer some further resistance following the sudden slide to 189 for 5, but too many wickets were gifted to a Surrey bowling attack depleted by the loss of Luke Fletcher to a back spasm after the on-loan seamer had sent down just six overs.
Nothing better summed up the nature of Kent's disappointing decline than the hard-hitting Coles's departure for 21 when the big left-hander tamely chipped a return catch to Jason Roy when he bowled a single over of his occasional seam just before Surrey took the second new ball.
Cowdrey was then leg-before to the deserving Matt Dunn for a grafting 39, and the same bowler soon wrapped up the innings by castling last man Ivan Thomas.
Kent club captain Key is playing under Sam Northeast's leadership in this game, having missed two Championship games after dropping himself following three unproductive four-day matches with the bat at the start of the season. But Key, who hails from Beckenham, has always enjoyed playing on the ground, which has not hosted any senior county cricket since 2012 due to the construction of a new 2000-seater stand, a new indoor school, and the addition of commercial and multi-sports facilities. He also has a magnificent career record against Surrey, against whom he has now scored 2096 first-class runs at an average of 63.51, with eight hundreds and ten further scores of 50 or more.
Key was soon at the crease from No 3, after Kent had won the toss but lost Joe Denly in the second over, and initially he featured in a stand of 49 for the second wicket with Daniel Bell-Drummond. Denly was leg-before for 0 to a nip-backer from Fletcher, and it could have been worse for Kent had Bell-Drummond not been dropped by Rory Burns at third slip off the second ball of the match, bowled by Dunn.
As it was, Bell-Drummond played nicely for 20 before pushing forward to an arm ball from left-arm spinner Ansari and being given out leg-before when the ball hit his front pad just before the inside edge of his bat.
But Northeast came in to hit nine fours and a driven six off Ansari in his 93-ball innings while Key - who has been playing in Kent's Second XI in order to regain his batting form - looked to gain quickly in confidence after advancing down the pitch to Ansari early in his innings and lofting a cleanly-struck six over long off.
There were seven fours besides, including the cover boundary which took him to his half-century, as Key sailed past his previous season's best of 34, made against Lancashire at Old Trafford in the last week of April. He had made only 86 runs in six innings before taking his self-enforced break from first team action, and last summer scored just 561 Championship runs at 22.44.
Just when it looked certain that Key would complete a ninth first-class hundred against Surrey, Key was adjudged lbw to a quicker ball from Ansari - although it seemed as if the batsman might have got some bat on it. He had faced 134 balls.
Two balls later Northeast edged Tom Curran to second slip, trying to force into the offside, and Darren Stevens then lifted a simple catch to mid off, driving at Dunn, to depart for a duck.
Billings and Cowdrey saw Kent through to tea at 224 for 5, but afterwards Billings was rightly livid with himself when he flashed at a short wide ball from Curran and edged a catch behind. They had added 46 for the sixth wicket but Calum Haggett was soon gone too, for a duck, nicking Curran to first slip as the sun and warmth of earlier in the day turned to cloud cover and plunging temperatures in the final session.