Kent 304 (Stevens 88, Ashwin 4-121) and 236 for 8 (Billings 100, Crawley 82) lead Nottinghamshire 124 (Stevens 5-39) by 416 runs

Sam Billings finally has something to smile about and English cricket should offer a cheer for that because he has values and talent worth cherishing. A summer that he has branded as the toughest of his career finally turned in his favour at Trent Bridge as he produced a happy-go-lucky century against a Nottinghamshire side who for long periods looked as if they can't wait for the season to end.

Let's call it the century where Kent's captain confirmed beyond doubt that they will retain their First Division status in their first experience of the top division since 2010.

It's pushing it a bit to write that. In fact, it's pushing it a lot, but you can just about get away with it, even though those who can be bothered to work out such things say it happened earlier because of bowling bonus points. Anyway it gives him something positive to remember the season by.

Billings returned to Kent from the IPL in April to dislocate his shoulder in his first game back, against Glamorgan in the Royal London Cup. He missed a winning England World Cup campaign - although in truth he might have missed the cut anyway - his return to the T20 Blast coincided with a lapse in form which meant that Kent unexpectedly failed to reach the last eight, and he began this match in the curious position (after only two Championship matches, one of which caused him to rail against the stupidity of the English fixture list) bottom of the Kent averages.

As someone who always gives the impression that he is the super-energetic, insatiably-optimistic sort of character who should be contractually obliged to appear in every cereal advert every produced, Billings needed life to offer him something positive as a return favour. A spanking century in 105 balls which probably came with a multitude of added vitamins should have done the trick.

The day ended, in suitable fashion, with his century - a blow down the ground against the left-arm spinner Liam Patterson-White - and then his dismissal as he tapped back a return catch. Kent, who reached stumps at 236 for 8, have a lead of 416 which feels a bit like unnecessary stockpiling.

Nottinghamshire, without a win to their name, did their best pleasure upon him, Paul Coughlin and Ravi Ashwin the main bowlers to suffer during a scintillating knock. They don't look in great shape.

Same dances in the same old shoes
Some habits that you just can't lose
There's no telling what a man might lose
After the thrill is gone

Cricket matches for one thing, not that The Eagles were thinking of that when they penned the song more than 40 years ago. But Nottinghamshire gave the impression at times at Trent Bridge that drudgery is upon them and they are desperate for a disastrous Championship season to end.

With their closest companions in distress, Warwickshire, in surprisingly domineering form against the leaders, Essex, they could yet go down this week and, if not, when the two sides meet at Trent Bridge in the penultimate game. The priority, whether or not anybody cares to admit it, is now to protect their state of mind for Finals Day in the Vitality Blast.

Kent might have anticipated a lead when they posted 304 on the first day, but they had no right to anticipate a lead of 180. They might have anticipated pushing ahead positively after gaining that lead, but not to the extent of rattling up 165 for 1 by the 34th over.

That Notts pegged it back by the close so markedly that they took seven wickets for 71 owed much to the stalwart qualities of Luke Fletcher, who sparked the fall of four wickets in five overs. Fletcher bulldozed a breach in the dam; Ashwin, who until then had been lapping against it then flooded through.

It took his captain, Steven Mullaney, a while to attract Fletcher's attention to suggest a second spell as he grazed at deep square - it was not the time to be gazing hopefully at the captain - but he responded with gusto, just as he had when he resisted for 90 minutes as a nightwatchman in the morning while others lacked his ingrained commitment to the cause.

He seamed back his first ball to cause Crawley, on 82, to drag on a square drive, finally ending a substantial stand that began when Jordan Cox, Kent's young No 3, had to retire hurt on 13 when he was struck on the forearm by Paul Coughlin.

Fletcher then twice passed Heino Kuhn's outside edge in an on-the-money wicket maiden that bore little resemblance to some of the ill-disciplined offerings that had served Kent so well until then and ousted him in his next over, feeling for a wide one to be caught at the wicket

Ashwin then caught the mood, finding enough turn to win two lbw decisions in the same over. Darren Stevens, the second victim, fell for a second-ball duck, pushing forward. In the first innings he had lumped the first ball he faced from Ashwin for six and probably wished he had tried it again.

But the afternoon session had belonged to Stevens. Told earlier this month that he won't be offered a contract extension by Kent, the 43-year old claimed 5 for 39, and reached 500 first-class wickets in the process, as Notts were dismissed for 124, a deficit of 180.

Notts captain Steven Mullaney, playing his first match for two months after knee surgery, needed lengthy treatment on a blow to his forearm before lunch and when he was lbw to the second ball of the afternoon session, the end was indecently swift.

Stevens then nipped out four more in only 5.1 overs as Liam Patterson-White edged to slip, Tom Moores was struck on the pad and, finally, Paul Coughlin kindly lofted to mid-on. Stevens raised his arms aloft, celebrating the 24th five-for of his career. He swung it a bit, but such a good pro must prefer the days when he is worked a little harder.

"Three more now for 500 for Kent," he said. Stats like that keep the old 'uns and good 'uns going when lesser players have long disappeared. And why ever not?

David Hopps writes on county cricket for ESPNcricinfo @davidkhopps