Derby County were emphatically beaten at QPR in John Eustace's first game as boss since returning to the club.

The Rams dropped into the Championship relegation zone as their goal difference took a battering at Loftus Road.

A rocket from Ilias Chair followed by Koki Saito's second goal of the season put the Rs in control at half-time.

Chair added his second from close range before defender Ronnie Edwards headed in his first goal since joining the club from Southampton on loan last month.

Jerry Yates had a late consolation disallowed after he had just strayed offside as the hosts secured a commanding win for Marti Cifuentes' side after two consecutive defeats.

Eustace was in the dugout just one day after his protracted move from Blackburn Rovers was confirmed.

And after a quiet 20 minutes the Rams were behind to a thunderbolt from Chair into the top corner - his first goal of the season.

The Morocco international harried Rams midfielder Ebou Adams into a mistake before getting the ball back from Michael Frey and smashing beyond Jacob Widell Zetterstrom.

Adams almost atoned for the error minutes later as he volleyed over Paul Nardi's crossbar in a strong spell for the visitors.

But from the moment Saito doubled the lead, the Hoops were in total control, as the Japanese winger lashed home after Zetterstrom had parried away Chair's cross-shot.

Hoops captain Steve Cook headed just wide of the near post as the hosts threatened to run away with it before Kenneth Paal made a vital block to deny Nathaniel Mendez-Laing at the other end.

The Rs carried on in the same fashion after the break but were almost undone as Marcus Harness forced a strong save from Nardi.

But Chair put the hosts out of sight with more than half an hour still left to play as he finished off a fine move at the near post created by Yang Min-Hyeok for his second of the game.

Edwards headed in at the near post from Paal's inswinging free-kick as Eustace's Derby return descended into a nightmare.

Rams striker Yates blazed wide from close range but had the ball in the net soon after only to be denied what would have been a footnote goal to offside at the end of a chastening defeat.

This was not in the script for Eustace and Derby.

The new Rams boss named an attacking side with Yates, Mendez-Laing, Harness and Lars-Jorgen Salvesen all in the starting line-up but the visitors offered little in the QPR third.

His side looked comfortable in the opening exchanges until Chair struck the opener with a thing of beauty.

By the time Edwards nodded in the fourth, Derby looked well beaten and have now gone 11 games without a win in all competitions.

Despite gesturing to the travelling fans to keep their chins up after the game, Eustace will know his side need a vast improvement if they can pick up any points in their next three games against Millwall, Middlesbrough and his former side Blackburn.

QPR boss Marti Cifuentes said:

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

"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."

On Ilias Chair: "I think Ilias is one of the best players in the league. I'm pleased that today he scored two goals, 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."

On Koki Saito: "Since day one he's looked very into the pace of the game, so it was about what he needed to learn tactically about the game, about the league itself.

"He has been showing that he's a really good player in the last third, fantastic in one v one on both flanks, especially on the left – he has a trademark where he is one v one on the edge of the box and is very difficult to stop."

Derby County boss John Eustace said:

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

"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."