Kent 507 (Bell-Drummond 153, Northeast 128, Billings 92, Coles 4-84) drew with Hampshire 351 (Ervine 121, Vince 70, Tredwell 4-102) and 248 for 9 (Smith 142*, Riley 4-36, Tredwell 4-110)
Hampshire are safely over the penultimate fence but dragged their hind legs through it. They just about avoided disaster against Kent via Will Smith's splendid rearguard century and now take a 10-point cushion into the final week over the fast-finishing Essex.
Hampshire were striding to promotion like Crisp to the 1973 Grand National with thumping victories over Kent at Canterbury and Leicestershire last week. But they were outplayed here and Essex are coming with another late surge, whittling down a 44-point deficit at the start of the month, and are looking to get up near the line like Red Rum in '73.
Hampshire's task remains straightforward. Any kind of victory at Glamorgan next week will see them promoted. But if Hampshire only draw, Essex will be guaranteed to pip them if they take 23 points against Worcestershire. If Essex draw at Chelmsford, Hampshire will need four points at Cardiff to guarantee promotion.
The margin for error at Glamorgan would have been far less without Sean Ervine, whose day three century produced three batting points that were wholly unexpected, and Will Smith batting through the final day to secure a draw.
"Over the last couple of days you've seen two of the best hundreds you're likely to see in the county game," Hampshire captain Jimmy Adams said. "The five points could be crucial, they might not matter, but in terms of the team showing resilience we've shown to be a tough team to beat this year. It's nice going into the last game with something riding on it."
Smith's century, his second in the Championship this season, capped a fine week where he also passed 1000 runs in a season for the first time and signed a new three-year contract with Hampshire. Crucially, he delivered five extra points for his side to give them a buffer for next week.
"I was due an innings like that," Smith said. "It was very very tricky. But over the years I've developed a method where I think I'm okay at staying in and gradually I've found a way to score as well. Given the situation, concentration wise and knowing what it means to the club to get those extra points it's got to be right up there as my best hundred."
Much credit is also due to No. 11 James Tomlinson, who held out gamely for Ervine in the first innings and Smith on the fourth evening. In total he ate up 69 deliveries in the match. Hampshire were also helped by the morning session on the final day being washed out in an electrical blaze.
Saving the game looked as straightforward as building a hotel on an empty piece of land with no planning restrictions with Hampshire only three down with 36 overs left in the day. But just as the collapse of the contractors stalled the hotel project at the Ageas Bowl, six wickets falling in 10.1 overs, including three in 13 balls straight after tea, held up Hampshire's promotion push.
Kent's two offspinners, Adam Riley and James Tredwell, shared eight scalps as the wicket began to crumble. When James Vince had slashed Calum Haggett to first slip - third man out, brilliantly caught by Darren Stevens - there was no hint of a problem. But the wicket began to turn.
Tom Alsop became the first of four lbw victims playing back to Riley, who then twice turned deliveries past the outside edge of Sean Ervine as signs of concern grew. In the first over after tea, Riley beat Ervine's inside edge to earn another lbw. There was no second rescue act. Matt Coles also got a good stride down the wicket but that still did not deter Nigel Cowley giving him out lbw.
Imran Tahir blasted Tredwell over long-on for six but, next delivery, Tredwell turned one past Tahir's forward grope and bowled him. Over 20 overs remained but once again Tomlinson held firm and Smith extended the lead to a safe distance. Kent captain Rob Key offered his hand with 10 overs left in the day.
Smith had little trouble against the spinners, getting well forward - particularly to Riley who bowls a little quicker than Tredwell - and right back to ride the turn. Unbeaten on 66 overnight after steadily seeing Hampshire through a potentially tricky third evening, he tucked and nudged his way to what he described as up there with his best centuries.
From early on in this match it was apparent Hampshire's final home match of the season would feature no promotion party - chairman Rod Bransgrove was away on business anyway - but the Ageas Bowl season still ended with an exciting day.
There is much about Hampshire on the field that can be likened to the hotel still being built at the Northern End of the Ageas Bowl. Eastleigh Borough Council have not quite had to step in to pay Jimmy Adams' wages or Imran Tahir's business class flight but like the hotel, the date of when Hampshire's Championship side are going to be back competing with the best in the country continues to be pushed back.
Both could be next spring, the latest completion date for the hotel and when Hampshire will begin their first campaign in Division One since 2011 should they gain the required points next week.