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The former Blackburn Rovers coach, who was officially announced as the new Derby manager on Friday, was allowed to appreciate fully the size of the task he has taken on as his side finished an 11th straight game without a win in all competitions.

"Really disappointed with the result, I've learned a lot about the group tonight," he said after the match.

"I'm excited about working with them next week. There's lots we can improve on and that improvement comes from work on the training ground.

"I think we started really well and the goal they scored knocked the wind out of our sails. And then you can see the group are lacking a little bit of confidence and unfortunately we didn't defend the box well enough for the second, third and fourth goals, so lots to improve on and that's what I'm excited about."

Derby hadn't look too bad in an uninspiring first quarter of the match, but all that changed when Ilias Chair fired Rangers in front with a blistering strike from distance that whizzed past Jacob Widell Zetterstrom in the Derby goal.

Koki Saito doubled the lead 10 minutes before the break, and the script went in much the same way in the second period as Chair slammed home a second before Ronnie Edwards glanced a header in for the fourth on 66 minutes.

Derby's Jerry Yates found the net late on, but his effort was chalked off for offside.

While Eustace was disappointed, Rangers boss Marti Cifuentes couldn't have been happeier after seeing his side bounce back after two consecutive defeats.

"I liked a lot of things, first of all the ability to bounce back after a disappointing last game," he said.

"I liked the fact that despite the fact we didn't start well the game, I was pleased with the efficiency that we showed to take the lead and then to take a bigger advantage before half time.

"We were angry after the last game and we wanted the three points and I think that was very important."

Cifuentes praised Chair for his contribution, calling him one of the "best players in the league".

"I'm pleased that today he scored two goals," Cifuentes said.

"He's not too happy with me because he wanted the hat-trick and I subbed him.

"He's a fantastic player and it's a bit sad that we missed him for such a long time at the beginning of the season.

"I'm happy that he's back [and] happy that he's performing well."