Somerset 30 for 2 trail Hampshire 196 (Dawson 103, Gregory 3-63) by 173 runs
Only twice this decade has a bowler ended a season with more than 50 Championship wickets at an average below 15, but after running through Hampshire's top order at the Ageas Bowl, Lewis Gregory has a fighting chance to put his name alongside Graham Onions and Morne Morkel in doing so.
Gregory's opening burst accounted for Felix Organ, Sam Northeast and James Vince within the first 40 minutes of play, and with new-ball partner Josh Davey and the returning Craig Overton picking up a wicket apiece, Hampshire were reeling at 24 for 5.
They soon fought back, primarily thanks to Liam Dawson's first Championship hundred in three years, but after bad light interrupted the final session, Somerset reached the close two down with the expectation of bright sunshine tomorrow.
A few years ago, it seemed that Gregory might never quite manage to fulfil his obvious promise. A former England under-19 captain, he had been a semi-regular wicket-taker in the Championship and an occasional contributor with the bat in white-ball cricket, but he had not quite kicked on in the way his club had once hoped, and back injuries were a constant source of irritation.
Fast forward to the present day, and he is perhaps the best English player on the circuit yet to win an international cap. In T20, he is a brilliant finisher, and attracted interest from Rajasthan Royals before last year's IPL auction, while in the Championship he is a precision engineer in his control of line and length.
Here, he was nagging and accurate, nipping the ball both ways off the seam. He struck with the third ball of the day, as Organ fended to slip, before removing Northeast - brilliantly caught in the gully by Roelof van der Merwe - and clean bowling Vince with a sharp inswinger.
"I've had a lot of issues physically which have held me back a little bit," Gregory said. "Someone asked me earlier in the year what the difference has been [this season], and I think it's purely been that.
"The skill has always been there, it's just being able to back that up, spell after spell. After a couple of operations it seems like I'm able to do that, so fingers crossed that continues."
Every man, woman and child in Somerset has underlined, circled and highlighted next week's apparent title decider against Essex in their respective diaries, but a win here and a Surrey victory at Chelmsford could feasibly be enough to seal the pennant with a game to go.
And at the stage of the season when every bonus point counts, Somerset had one within half an hour of the first morning of their penultimate game. On a pitch with a healthy covering of grass - Nigel Gray's final home surface as Hampshire's groundsman - both sides surprisingly wanted to bat, though Vince must have instantly regretted his decision.
In the game between these sides here last summer, 34 wickets fell in five sessions as the final nail was hammered into the coffin that contained Somerset's title hopes by teatime on the second day; after the early flurry of wickets, it seemed a repeat was on the cards.
But during a vital stand of 92 between Dawson and Keith Barker, who made a doughty 40, batting suddenly began to look easy.
"I think the ball got a little softer," suggested Gregory. "It was hard to keep the ball in good condition. There was a little bit in the surface with a hard seam, and it seemed to nip around a little bit, so fingers crossed we can play well first thing in the morning, and with the sunshine out we can make hay."
Dawson has had an unusual summer, with a two-month stint carrying the drinks as part of England's World Cup squad punctuating an otherwise unremarkable campaign, and he had off-field distractions to contend with in the form of lucrative contract offers from both Surrey and Warwickshire.
Instead, he signed a new three-year deal at Hampshire, and was the only man to look comfortable against Somerset's persistent attack. He seized on width well, playing the ball late under his eyes, and brought up his hundred with an elegant straight drive through mid-on.
It would have been a source of immense frustration that he was dismissed in such tame fashion, flashing at a back-of-a-length ball from Tom Abell with minimal foot movement, but if this wicket proves to be low-scoring, his 103 runs may prove to be worth plenty more.
"It is one of the quickest pitches I've played on here in the last couple of years," said Dawson. "There is more bounce and zip than usual. When it is doing something, it is doing it quicker."
Rilee Rossouw has played his final game of red-ball cricket for Hampshire. The South African batsman hinted at the start of the season that he was unlikely to extend his deal beyond this season, and will only play T20 for the club next year. It is as yet unclear as to whether he will attempt to resume his international career.
Meanwhile, Tim Groenewald is set to leave Somerset after five-and-a-half years at the club. His contract expires at the end of the season, and it is expected that Kent will announce him as a new signing in the coming weeks.