The Serbian striker netted either side of a Lyndon Dykes strike to help the Cottagers to a win over their West London rivals, fellow forward Bobby De Cordova-Reid and Antonee Robinson were also on the scoresheet.
Story of the match
After a slow start to the game, it was the hosts who opened the scoring, Neeskens Kebano did well to hold the ball up on the right and played it back to Denis Odoi, whose cross found Mitrovic who brought the ball down on his chest under pressure from Rob Dickie, before firing beyond Seny Dieng to give the hosts the lead.
Fulham went close again when Joe Bryan collected the ball and fired over the bar from distance.
Fulham went close again soon after, Harry Wilson's corner was flicked on by Mitrovic but Dieng made a smart stop at the near post, before, Jean Michael Seri saw his effort blocked brilliantly by Yoann Barbet.
The hosts went close again soon after, Wilson saw an effort deflected behind for a corner, which the visitors managed to clear, before, Wilson clipped the ball into the path of Ivan Cavaleiro, whose header was claimed by Dieng.
The visitors had yet managed to get going, however, Moses Odubajo crossed well to Chris Willock at the back post, Willock managed to take a touch before firing an effort back off the post.
Fulham tried to extend their lead before the break, Wilson saw his effort hit his own team-mate Odoi before Tim Ream fired over.
Half Time: Fulham 1-0 Queens Park Rangers
The first chance after the interval fell the way of the visitors, Ilias Chair played a lovely ball to Sam McCallam, who got beyond Odoi and he pulled the ball back but Marek Rodak dived to gather the ball.
Soon after the visitors were level, Willock did well driving inside from the left played in Dykes, who rounded Rodak before slotting home.
Fulham tried to regain the lead when Reed fired an effort from distance which bounced just wide, soon after the hosts did retake the lead.
Kebano delivered a superb cross, Mitrovic managed to shrug off the defending of Jordy de Wijs to head home his and Fulham's second goal of the game.
Fulham then extended their lead when Seri played a good through ball into the path of De Cordova-Reid who fired into the far corner to extend the lead.
Defender Robinson then put the cherry on the Fulham cake with a superb goal. He charged forward down the left, cut-inside and fired an effort beyond Dieng via a deflection off De Wijs to extend the hosts lead.
Full Time: Fulham 4-1 Queens Park Rangers
Impressive display from Fulham
It was an impressive performance from Fulham who after opening the scoring on 10 minutes never looked back. The hosts could and probably should have had more from what their performance showed but some good saves from Dieng kept the score down.
Fulham: Rodak, Odoi, Adarabioyo, Ream (capt), Bryan (Robinson 58), Reed, Seri, Cavaleiro (De Cordova-Reid 32), Wilson (Chalobah 77), Kebano, Mitrovic.
Substitutes (not used): Gazzaniga, Mawson, Cairney, Muniz.
Goals: Mitrovic 10', 67', De Cordova-Reid 71', Robinson 90+1
Booked: To appear here
Queens Park Rangers: Dieng, Odubajo, Dickie, De Wijs, Barbet, McCallum (Dunne 66), Ball (Dykes 46), Johansen (capt), Willock, Chair, Austin (Gray 69).
Substitutes (not used): Archer, Amos, Duke-McKenna, Adomah.
Goals: Dykes 55'
Booked: Ball (foul), Johansen (foul), Odubajo (foul), Dunne (foul)
Referee: Oliver Langford (West Midlands)