Derbyshire 287 for 3 (Guptill125, Durston 120*) beat Unicorns 158 for 9 (Hughes 5-29) by 129 runs
Scorecard
Former Unicorns right-hander Wes Durston struck an unbeaten century to help Derbyshire to a comfortable 129-run win over his old side. New Zealand opener Martin Guptill joined Durston in reaching three figures as the pair combined in a decisive double-century stand that formed the basis of Derbyshire's 287 for 3.
The Unicorns never came close in pursuit as they managed 158 for 9, with part-time spinner Chesney Hughes bagging a career-best five for 29 on his return to the side.
Durston secured a return to county ranks with Derbyshire following an impressive inaugural season with the Unicorns three years ago, but he was short on thanks for them at the picturesque Sir Paul Getty's Ground in Wormsley. The 31-year-old blasted an unbeaten 120 from 111 balls, which included 11 fours and a six.
Guptill was even more punishing as he reached 125 from 102 balls before Glen Querl had him caught by debutant Michael Roberts. That ended the 222-run second-wicket stand that took 31 overs after Hughes was trapped lbw by Warren Lee.
The duo dominated the Unicorns attack, most notably former Lancashire paceman Steve Cheetham who, after delivering an early maiden, went for 53 from his next five overs.
The Unicorns' chase got off to a bad start with Tim Groenewald removing openers Michael Thornley and Roberts early. Former Leicestershire wicketkeeper-batsman Tom New and former Warwickshire batsman James Ord then set about repairing the damage in a 46-run stand, but the Unicorns middle-order fell apart as they lost four wickets for 10 runs.
It was Hughes' part-time spin that did the damage as he removed both New and Ord before also snaring skipper Keith Parsons. Hughes went on to complete his five-wicket haul when he claimed Querl and Lee in the same over to cap a resounding win to start Derbyshire's Group C campaign.