Derbyshire 160 for 4 (Came 43, du Plooy 40*) beat Northamptonshire 156 for 8 (Gay 47, Zaman 3-26) by six wickets
Having won the toss and opted to bat, the Steelbacks lost Ricardo Vasconcelos in the opening over, pinned leg before by offspinner Alex Thomson. That wicket ushered Chris Lynn to the crease and the big-hitting Queenslander pulled a short ball from Zak Chappell over midwicket for six, combining brute power with shrewd placement as he reached 33 from 23.
However, attempting to smash Thomson's first ball after the powerplay over the top, Lynn picked out the long-on fielder and Derbyshire cemented control as George Scrimshaw sent Justin Broad's middle stump cartwheeling. Scrimshaw also picked up the prize wicket of David Willey, caught behind off a miscued pull and that meant the Steelbacks needed Gay, who had seen little of the strike early on, to hold their innings together.
The left-hander seemed on the verge of his second T20 half-century, having steered Zaman to the cover boundary to reach 47 - but the Pakistan international had the last word with his next delivery, a fast swinging yorker that took out Gay's leg stump.
It was a similar tale for Saif Zaib, whose leg-side maximum off Zaman took him to 25 from 13, only to punch his next ball straight to long-off and it needed Ben Sanderson's audacious ramp for four in the final over to haul Northamptonshire above 150.
However, the Falcons found it hard to get the ball away at the start of their reply, stuttering to 37 in the powerplay for the loss of Luis Reece and Haider Ali - the latter giving Tom Taylor the charge and skying into the gloves of Lewis McManus.
Taylor was unfortunate not to add the scalp of Madsen, who survived a compelling lbw appeal before he had scored and capitalised on that close call by drilling the bowler back down the ground for four. There was also frustration in the field for Taylor, who did well to prevent Came's drive off Freddie Heldreich from crossing the long-off fence, but could not hold on after palming the ball back into play.
Madsen continued to milk the bowling cleverly until Willey brought himself back on to bowl the veteran for 35 from 24 and, with pressure building, Came holed out to deep midwicket soon afterwards. But du Plooy kept the scoreboard moving along, finding the boundary regularly enough to keep Derbyshire in touch and drove Sanderson for six in the penultimate over before Taylor conceded four wides to end the contest.