Danny Ward scored after just 47 seconds as Huddersfield beat Derby to continue their encouraging start to life back in the Championship.
Ward's goal from Adam Hammill's cross was enough for the Terriers to claim their second win of the season.
After a terrible start, Derby played some attractive football but they were unable to rescue a point.
Conor Doyle spurned a great chance to equalise when he fired over the crossbar in the second half.
Huddersfield have lost just once since returning to the second tier and look increasingly assured as they climb to eighth in the table and remain unbeaten at home.
The visitors sit 19th with five points from five games, and after their team coach was late arriving because of heavy traffic, Nigel Clough's side were caught cold on the pitch.
Winger Hammill, on loan from Wolves, raced down the right flank unchallenged and was allowed to pick out Ward, who got in front of his marker and diverted the ball past Frank Fielding with a neat right-foot finish.
The Rams belatedly found their stride with some slick passing and movement. And it needed a great last-ditch tackle from Huddersfield captain Peter Clarke to prevent Derby striker Conor Sammon levelling from Jamie Ward's lay-off in the first half.
Derby's revival continued after the break though it was Huddersfield who almost doubled their lead when Adam Clayton's shot was tipped round the post by Fielding.
But the visitors were seeing more of the ball and Doyle failed to stretch home goalkeeper Alex Smithies from another fine Ward ball, before the Rams felt they had a strong case for an injury-time penalty.
However, referee Trevor Kettle waved play on when Jeff Hendrick fell in the area after a strong aerial challenge and the Terriers held on for victory.