Northamptonshire 273 and 331 (Vasconcelos 88) beat Sussex 106 (Sanderson 6-37) and 105 (Sanderson 4-18, Hutton 4-32) by 393 runs
Northamptonshire claimed their first County Championship win of the season after Sussex's batsman capitulated for the second time in the match to lose by a record 393 runs at Hove.
Having been bowled out for 106 in their first innings, Sussex fared even worse as they were dismissed for 105 after another abject batting performance. Their margin of defeat was the heaviest in their history in a County Championship game.
Sussex's coach Jason Gillespie, who is desperately seeking the right formula in both batting and bowling ranks for a county plagued by inconsistency, said: "That was an unacceptable performance and there has to be a lot of self reflection as individuals on areas where we have to improve. We didn't score enough runs and the lads have to work out what they can do better to get the job done.
"We haven't batted well enough obviously but yesterday afternoon I thought our body language and our bowling was very disappointing and we allowed Northants to take the game away from us.
"I can't take anything away from them - Ben Sanderson and Brett Hutton bowled really, really well - but we were blown away again today. We need to be better all round. There was a great opportunity today for someone to put a big score on the board and we weren't able to do that. We need more lads to put their hands up than guys like Ollie Robinson and Ben Brown. We've had a couple of tough games but we need to be better."
They seemed to be making a better fist of things when Varun Chopra and Luke Wells took the score to 35 for 1 but Sussex then lost nine wickets for 70 runs with Ben Sanderson and Brett Hutton again wreaking havoc.
Sanderson's 4 for 18 in two spells included the 200th first-class wicket of his career. He finished with match figures of 10 for 50 while Hutton improved on his 3 for 47 in the first innings by taking 4 for 32 in the second to finish with a match haul of 7 for 79.
There were boos from some Sussex supporters when a second successive defeat was confirmed shortly after 4pm. Although they remain third in Division Two they have played a game more than most of their rivals, many of whom could overtake them depending on results in the other matches which finish on Wednesday.
Once again Sussex's batsmen were like rabbits in the headlights against a relentless Northamptonshire attack who found a consistent length and enough seam movement and swing to take nine wickets in 19 overs during the afternoon session.
Sussex began their notional pursuit of a target of 499 25 minutes before lunch but they didn't get to the interval unscathed with Phil Salt pinned in Hutton's second over for one of three ducks in the innings.
The experienced Chopra, who is on loan from Essex, and Wells, negotiated 12 overs either side of lunch but when Wells (11) nibbled fatally at Hutton's away-swing the innings went into a dramatic tail spin.
Laurie Evans (3) became Hutton's third victim and with the score still on 41 Chopra (22) was caught behind off Nathan Buck, who then had Delray Rawlins (8) taken mid-off off a mis-timed pull.
Skipper Ben Brown decided to go down fighting, hitting five fours and two sixes - both in the only over bowled by off-spinner Rob Keogh - as he dominated a sixth-wicket stand of 28 with David Wiese.
But when Sanderson returned to the attack Sussex's last five wickets disappeared for 13 runs with Sanderson removing Wiese and Will Beer in the space of three balls before Keogh clung on to a good catch in the gully to remove Brown for 46 in the paceman's next over.
Sanderson finished things off by bowling Aaron Thomason, Hutton having picked up his fourth wicket when wicketkeeper Adam Rossington held his fourth catch of the innings to remove Ollie Robinson.
Earlier, Buck hit a 59-ball half-century as Northants added a further 119 runs during the morning session before being bowled out for 331. Resuming on 212 for 4, they lost their first three wickets to Robinson, who finished with match figures of 10 for 132. His performance was the lone positive for Sussex.
Buck was dismissed two balls after reaching his half-century when he top-edged a pull at Abi Sakande before left-arm spinner Rawlins picked up two wickets to finish with 3 for 34.