Derbyshire won their first game of the season at Hove and put a big dent in high-flying Sussex's Division One title ambitions.
Sussex had earned a first innings lead of 40 and began the third day on 11-1 in their second innings, but they were ripped apart by Tim Groenewald (5-40) as they were skittled out for 133.
And the visitors proved there were no devils in the pitch, Ben Slater (66no) and Wayne Madsen (62no) knocking off the target of 174 in quick time to seal a thumping nine-wicket victory with more than a day to spare.
The experienced Groenewald got Derbyshire off to a flier by dismissing first-innings centurion Luke Wells (2) with the third ball of the day, Peter Burgoyne taking the catch at third slip.
Mike Yardy (11) then nicked a nasty lifter from Mark Footitt behind and Groenewald pinned nightwatchman in front for 5.
Footitt then trapped Rory Hamilton-Brown (5) lbw to leave Sussex floundering on 29-5.
Skipper Ed Joyce (17) and Luke Wright (49) spent 15 overs stoutly adding 33 runs for the sixth wicket. But debutant Matt Higginbotham ended the partnership by having Joyce adjudged lbw and another debutant, Alex Hughes - another right-arm seamer - did for Ben Brown (11), who steered him to first slip Shivnarine Chanderpaul.
Wright and Chris Jordan (23) added 37 to ensure that Sussex would at least have something to bowl at, but Groenewald returned to dismiss both.
Wright nicked him behind and Jordan lost his leg stump trying to pull him, whilst Footitt got his third wicket by trapping Steve Magoffin in front for one.
With Magoffin, Jordan, Hatchett and Monty Panesar in the Sussex attack, 177 was not necessarily an easy target, particularly as Derbyshire had not won a game all season.
But Hughes and Slater set the tone with a fluent, attacking opening stand of 64 in just 14 overs.
Hughes hit a six and three fours in his breezy 34 before offering no stroke to Jordan and losing his off stump.
But skipper Madsen, who hit 97 in the first innings, ensured there was to be no slip-ups and kept up the scoring rate at around four an over against all the bowlers and they got home after tea to spark scenes of jubilation in the Derbyshire dressing room.