Fulham boss Marco Silva was left frustrated after their 3-2 defeat at Brentford on Monday night.
Silva says the hosts deserved the win, though questioned the penalty awarded to them.
Silva said, "Tough game. They were more aggressive than us. They were stronger. We conceded goals in the first minutes of both halves.
"We reacted well and started to play our game some moments. We didn't start the game the way we should. We reacted well and equalised. Again we started the second half sloppy."
On Brentford's penalty, he added: "It's a harsh decision from the referee. He's one of the top referees in this competition. I know what it means to play derbies. This can be a VAR decision.
"It's difficult to understand why in a competitive derby we give these kind of decisions. It was a surprise for me. They deserved the three points, they were more aggressive than us. They played in their way.
"We'll not change what we've been doing. We have to be honest as well. The best way for us to improve is to be honest when we analyse the game, make the players understand we weren't at the standard we should be."