Hampshire 219 and 172 (Vince 56, Jacks 5-87) beat Surrey 207 and 132 (Sudharsan 40, Dawson 4-53) by 52 runs
Hampshire dampened Surrey's celebrations within half-an-hour's play on the final morning at the Ageas Bowl, to become just the second team to beat them across their back-to-back LV= Insurance County Championship titles.
Only Lancashire had beaten Surrey in red-ball cricket in either 2022 or 2023, winning once in each campaign.
But Liam Dawson took his season tally to 49 wickets by taking two of the four wickets needed to secure victory, with Surrey only scoring 20 of the 73 required to lose by 52 runs before 11am.
Despite the defeat, Surrey were presented with the Division One trophy by ECB chair, and former club chair, Richard Thompson.
"It was a weird way to get over the line halfway through yesterday," Surrey's head coach, Gareth Batty, said. "But the County Championship is set up over six months - you don't win it over one day or one game.
"It is the marathon cup and you still have to still celebrate it and respect it, even if you are on the wrong end of the result today.
Surrey had made it clear throughout the match that they had the intention to finish their triumphant season off with a victory.
That plan was skewed somewhat after they were confirmed as champions before lunch on day three, and their celebrations continued after play concluded.
It took five balls for Jordan Clark to advance to Mohammad Abbas and prod to James Vince at first slip.
Jamie Overton came out and played a delicious straight drive, and then a powerful sweep shot.
But he was less gainly when his agricultural swing saw him stumped by Ben Brown off Dawson, the start of three wickets to fall in 12 balls to end the year.
Kemar Roach departed second ball when his wild swing flew to first slip, with the Abbas and Vince combo striking again. The Pakistan seamer ended the campaign with 53 scalps.
Sai Sudharsan, with 73 in the first innings, batted sensibly until Dan Worrall arrived and hacked at one, at which point his stylish 40 turned more towards aggression.
The Indian took on Dawson but only managed to top-edge to Vince running across from the slips to end the contest and the season.
Batty admitted the result was a disappointing way to finish, but acknowledged the peculiar circumstances had played a part.
"We completely understand why because we had already got to the point we had driven towards all season, and that was to lift the trophy again," he said.
"There was no blame to anybody or no nothing. We almost scratched today off because it was all about yesterday when we got over the line."
Hampshire finish third for a second year in a row having won eight times - the same as the champions.
"It is nice to finish with a win. First of all though, credit to Surrey for winning it they have been the stand-out team across the whole season and they deserve to be champions," James Vince, Hampshire's captain, said.
"We've finished off with three wins in a row including Essex and champions Surrey. We made finals day, lost in the final of the One Day Cup and finished third in the Championship. It is one of those years where you have been there or thereabouts in all competitions but have nothing to show for it.
"It is tough to win trophies but we have been consistent across all formats for the last two or three years."
