The London club were well worth their 3-0 win over lacklustre Derby.
Bobby Decordova-Reid gave them the lead after seven minutes with his first goal for the club, beating Derby goalkeeper Kelle Roos to a cross by Aboubakar Kamara just two minutes after Tom Lawrence had miscued a good chance to put Derby ahead.
Fulham's present three-game run of wins followed a 3-0 home defeat against Hull and Parker praised his players' reaction.
"Sometimes you wonder how you have lost a game, but after the Hull game we held our hands up and said we underperformed and were not the team we are or that I wanted us to be," Parker said.
"We needed a reaction against Birmingham and we got that, and then again against QPR and now we have won three on the bounce and that is massive.
"We showed another side to us tonight. We were fortunate against QPR but what pleased me most is that we saw a team of players who executed the game plan tonight.
"We limited them to no shots on target and that was our application and our base. And from there we have the quality to build attacks and be deadly and we were that today."
Parker singled out Mitrovic for praise after his return to the team following a ban.
The Fulham boss said: "Last week he rested through suspension and he came into this game rested and with only one thing on his mind – to get three points. And we did that."
Derby have won five successive home games but have not taken three points away from Pride Park since the opening match of the season.
"The away games, they need a different mental focus to get results and this is something we have to talk about," Derby manager Phillip Cocu said.
"But you still have to find a way. At the moment we haven't apart from the first game and that was a long time ago."
One factor that could change that will be the arrival of Wayne Rooney as player-coach, which may happen as soon as this weekend's home game against QPR.
Cocu said: "I think so. He could be in the dugout. He had to plan his holiday break after the MLS season.
"He will be important for us because he is a natural leader and this is something we still struggle with.
"Reading the game, seeing what is necessary at moments and also verbally if somebody is not doing his job, getting everybody switched on.
"We don't have to talk about him as a player, but his experience will be very important for a lot of the young players in the squad."