The Bulgarian ace netted a double as the Cottagers held onto a three-goal lead when the R's came back hard at the end.
It was the opening 20 or so minutes which won it for Fulham and Berbatov says he noticed Samba was looking slightly nervous at the beginning so decided to press him which led to mistakes for both of the home sides opening two goals.
"Yeah, you can see [players are nervous] sometimes," Berbatov told Sky Sports. "In the first couple of minutes you can see which players look nervous or [who] is having a bad game.
"So you try to push and press on them, which was the case with their player when we scored the second goal. You need to be clever in a situation like this because if you take advantage of them like you should, we score."
The former Manchester United star added: "It's great, I'm enjoying my football here. You can see it on the pitch, by the goals I score and the way I'm playing. It's going great for me, and for the team, so I hope it continues this way.
"We've always been safe. I don't see why anyone should worry. We play good football and sometimes we make childish mistakes which is why we suffer, but if we correct this we will be even better."