Hampshire 319 (Wheater 102, McManus 56, Dawson 54) and 393 for 7 dec (Adams 99, Alsop 93, McLaren 71, Dawson 69) beat Nottinghamshire 245 (Read 70*, Carter 4-52) and 291 (Mullaney 137, Taylor 58, Wheal 6-51) by 176 runs
The excitement gathering around Nottinghamshire's trip to Twenty20 finals day on Saturday is being tempered somewhat by the growing likelihood that they will playing their four-day cricket in Division Two next season after the fleeting vision of a highly unlikely victory proved to be a mirage.
It may be a destination that Hampshire will also have to contemplate but this victory, only their second of the season, in which Brad Wheal, the 19-year-old pace bowler, claimed his maiden five-wicket haul gives them at least a chance to stay up. Surrey's victory over Warwickshire does not help them in that respect but Warwickshire themselves as well as Durham suddenly look more vulnerable than before.
Nottinghamshire, whose batting has been brittle for much of the season, reached 243 for 3 after Steven Mullaney and Brendan Taylor put on 162 for the fourth wicket, which made a record fourth-innings target at least theoretically possible.
But the loss of Mullaney and Samit Patel to consecutive balls from Wheal sparked a collapse that saw five wickets fall for 17 runs in the space of 49 balls, after which effectively only Imran Tahir and Harry Gurney stood between Hampshire and victory, neither of whom was ever likely to present a lasting impediment.
Will Smith, the Hampshire captain and former Nottinghamshire batsman, hailed what he hopes will be a turning point in the club's fortunes.
"While Mullaney and Taylor were going well there was even a slight chance they could push for a win but on day four things can happen very quickly and credit to Mason Crane and Brad Wheal that they did, with quality spin and fast bowling," he said. "But everyone in the attack bowled exceptionally well to set things up.
"We knew too with the old ball as we had it, soft and pretty scuffed up, reversing a little bit and skidding through, that it would be hard for anyone coming in. There was always a sense that if we got one wicket we could get a few.
"It has been a hard season with the tragic passing away of Hamza Ali and what's happened to Michael Carberry, plus all the injuries to the bowlers, but there is a sense that we are getting some momentum at the right time and we have to take positives from last year, getting three wins in the last four games or whatever it was, and believe that we can still do it."
Chasing 468 to win, which required them to exceed the county record for a successful fourth-innings run chase, Nottinghamshire they began the final day at 42 for 2 thinking only about survival, yet after Hampshire managed to prise out only one wicket in the morning session, Mullaney and Taylor began to enjoy a sense of gathering impetus in their fourth wicket partnership.
Although Taylor, who has been out of form much of the season, was hardly fluent, with Mullaney very much the opposite, readily picking out the balls he could hit and usually despatching them efficiently, there was a moment with around 60 overs remaining that the required rate was only a touch more than five an over.
Yet in the steaming heat the possibility vanished almost in the blink of an eye.
Wheal, who had accounted for Michael Lumb in the morning session as the former England batsman drove loosely outside off stump, surprised Mullaney with a delivery that climbed off a length, the ball looping into the air off the leading edge, to which Gareth Berg responded by running in from mid-off to take a good diving catch.
Then Smith's one-wicket-brings-another theory paid off as Samit Patel fell first ball, caught behind down the leg side. Crane, the legspinner and another 19-year-old, had Taylor caught low down at slip and as tea was taken Nottinghamshire's comfortable position had gone, 245 for 3 rapidly transformed to 259 for 6.
Two balls after tea, Crane claimed his third of the innings as Luke Wood flicked a ball off his hips straight to Ryan McLaren at leg slip and when Wheal thudded one skiddily into Jake Balls pads there was no way back. In the event, Tahir survived as Chris Read shouldered arms to another delivery that kept low and Gurney lasted three balls before his off stump was flattened.
Mick Newell, Nottinghamshire's director of cricket, was typically blunt in his assessment, with his side now 30 points adrift of seventh-placed Durham, who have a game in hand.
"If we keep playing as poorly as that we will get what we deserve," he said.
"To say we might have been distracted by Saturday would be an easy cop-out. The truth is that this is just the continuation of some pretty ordinary four-day form, we haven't suddenly produced a poor performance out of nowhere. And one fifty and one hundred from the top six on a pretty flat wicket is pretty ordinary.
"It was a game neither side could afford to lose and by doing so we have put ourselves under a lot of pressure in the last four matches."
Stuart Broad is expected to be available for at least a couple of Nottinghamshire's remaining matches, but Yorkshire, Durham and Somerset away, with Championship leaders Middlesex the only side still to come to Trent Bridge, look daunting fixtures.
Hampshire, with Somerset and Surrey away, Yorkshire and Durham at home, hardly face an easy run-in and there is still a gap to close. Yet, given the chance, Nottinghamshire would certainly swap.