Kent 285 for 4 (Denly 88, Crawley 69, Bell-Drummond 64, Kuhn 50*) lead Surrey 271 (Elgar 63, Foakes 60) by 14 runs

Surrey have doubtless endured more frustrating days in their time, but they might be struggling to remember when. First the yes/no switch of the ailing Gareth Batty for Amar Virdi, then the refusal of the umpires to change an unusually smelly ball, and finally an innings of true international quality by Joe Denly that has given Kent the upper hand in an enthralling first division contest.

It is easy to forget that Denly holds possession of the No. 3 spot in England's Test side. This might be because so much has happened since the most recent fixture, against West Indies in February. Denly scored 69 in second innings in St Lucia, his best over four Test innings. But white-ball activity has dominated, and he lost his place in the World Cup squad to Liam Dawson despite selection for the initial fifteen.

Being exposed in an ill-conceived role of one-day wrist-spinner does not mean his time is up as a Test match batsman. As he is showing. Two games ago he scored an unbeaten 167 for Kent against Nottinghamshire at Tunbridge Wells. Here, while ultimately 12 short of a second century of the season, he was well-organised against good, varied pace bowling on a pitch showing signs of low bounce. The best players always offer the illusion of having more time to play.

With additional half-centuries from Zak Crawley, Daniel Bell-Drummond and Heino Kuhn, Kent opened up a lead of 14 having taken only half-an-hour in the morning to secure the remaining Surrey first innings wickets. Three, rather than four, because the ECB over-ruled an agreement by the counties, originally supported by Steve Davis, the Board's cricket liaison officer, that Virdi could replace Batty, who had fallen ill overnight.

The consequences of the decision - fully in line with competition regulations - was felt later when Rory Burns was left with four seam bowlers but no specialist spinner. Scott Borthwick might have twirled for England in Australia five years ago, but his overs now were his first of the season. Like Sam Curran earlier, he was warned for running on the pitch. Meanwhile, Virdi could do no more than field as twelfth man, but at least Batty will be able to play a part over the next two days if he recovers.

If the episode felt a touch bizarre, it was almost matched by the tale of the pungent ball. The problem arose when a shot leapt over the fence into a small area in front of some green silage bins. These had started to leak after recent rain, forming small, unpleasant puddles of particular interest to flies. The idea of rubbing spit into the ball once returned was quite unappealing, and while Rory Burns might have found Lambeth Council's 'elf and safety team receptive to a change, the umpires refused.

Burns debated the matter passionately with Billy Taylor, then again as the players went off for lunch. By then, Crawley and Denly had begun the recovery following Sean Dickson's flawed decision to shoulder arms to Curran, and a tone was set for the afternoon. The final disappointment for Surrey arrived at around 6.30 when play concluded early a couple of overs after they had taken the second new ball which Denly compliantly forced to deep gully.

The gasholder outside the ground still bears a promotional banner proclaiming "the world's greatest cricket celebration". Something to do with a tournament about to reach its semi-final stage. The World Cup has come into its own, but there was plenty to celebrate in this county contest too, not least a passage after tea when Denly came through the best that Morne Morkel at his nastiest could offer with pace and steepling bounce.

He had earlier struck Bell-Drummond on the helmet and continued to signal intentions with two men out and, at times, a short leg. Denly handled expertly all that was sent his way, swaying or ducking and keeping his hands low. If anything, skiddier short ones from the slippery Jordan Clark caused more problems, at least until the extra lift of the second new ball surprised him after 319 minutes at the crease.

Denly looked stunned at his own mistake, mirroring the reaction of Crawley to his own dismissal. Crawley's 69 from 105 balls featured 13 fours, a reflection of the way he waited for bad balls to dispatch and did not worry too much about the rest. Like Denly, he left well, but he may have been ruffled by a loose slash at Clark two balls before the bowler enticed an edge that Borthwick held low to his right at second slip.

Bell-Drummond might have gone first ball with a drive that seemed extraordinary for a player with a background in opening. Perhaps speculation that Jason Roy is to open in the Ashes is tempting others to imagine that is the way forward. But the brush with mortality seemed to remind Bell-Drummond of who he is. He played very nicely from then on, unruffled by the blow that struck. Finally, Kuhn entered to take advantage, recording the quickest of the four Kent fifties from 57 balls.