Captain Jimmy Adams led the way to help Hampshire chase down a victory target of 326 with almost two overs to spare as Northamptonshire crashed to an eight-wicket defeat at Southampton.
Adams made 149 before departing with only 49 required as Hampshire eased to their fourth win of the season to maintain their strengthening promotion challenge.
The opener hit 23 fours and two sixes from 216 balls and after his departure, Simon Katich’s unbeaten 61 made sure of Hampshire’s victory.
Northants left the south coast wondering how they had conceded a powerful position, put together over the previous three days.
They went into the last day on 176 for five in their second innings, a healthy lead of 256 and with Hampshire struggling to avoid defeat.
Chris Wood bowled James Middlebrook in the third over of the day and David Murphy was out one run later at 182, caught in the slips by Neil McKenzie off David Balcombe.
But Alex Wakely accelerated towards the declaration with an innings of 96 from 191 balls but, seeking the boundary to take him to his third first-class century, could only edge Kabir Ali to Liam Dawson at slip.
With his dismissal at 245 for eight, Northants declared leaving Hampshire to score their runs in 72 overs on a wicket less helpful to the pace bowlers than it had been over the first three days.
Hampshire responded positively with Adams and McKenzie putting on 150 for the first wicket in 39 overs with South African McKenzie using his experience to make 76 with 12 fours.
Katich then joined Adams and, as Northants struggled for a further breakthrough, took the score to 277 before Adams lifted Luke Evans to Wakely in the covers.
But there was plenty of time for Katich and Dawson to get on top of the tiring bowling to rush Hampshire home.
Katich took Hampshire to their target with his sixth four while Dawson played a valuable supporting role with his 27 not out.
Evans, who had also got rid of McKenzie, finished with two for 75 but the rest of the Northants attack failed to rise to the challenge.
Hampshire, who moved into second in the LV= County Championship Division Two, now have three matches left to regain the top-flight status they lost last season.