Derby begun life under new manager Paul Warne with a 2-0 victory at Cambridge thanks to two goals from James Collins.
Nathaniel Mendez-Laing fired wide in the opening moments for the away side, while the hosts threatened in the 34th minute when Shilow Tracey’s corner fell to Jack Lankester, who shot wide on the turn.
Four minutes later Cambridge had goalkeeper Dimitar Mitov to thank to keeping them on level terms as he parried Conor Hourihane’s powerful effort from an angle.
But Mitov was helpless in the final minute of the half when Zeno Ibsen Rossi failed to deal with a long ball and gifted a chance to Collins, who fired home to put the Rams ahead.
Hourihane missed a big chance to double the lead after an hour when he could only fire into the side netting following Tom Barkhuizen’s cross from the byline.
With Cambridge pushing for a leveller late on, Derby broke and Max Bird played in Collins, who beat Mitov at his near post to put the seal on County’s first away league win of the season.
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.