Sitting on 36, he is eight clear of former United striker Ruud van Nistelrooy.
On his success from the spot, Fernandes said: “When you take so many penalties, you need to change.
“Also because the goalkeepers start looking at you, study you and everything so, as they do that, I do the same as them.
“I study them, I know what they do, what kind of movements they do for all the different penalty takers they are against. I see what their accuracy is against each other, then I get my chance, but all of these things always depend on the moment in the game.
“I feel more comfortable doing the 'jump' and waiting for the goalkeeper to make a decision. I think it's the more accurate one. But if I have to change it because I think, by doing that, I'm giving them something extra to save it, I will do it differently, to try to not give anything away to them.
“You can still miss, but at least you know everything you're doing is for a reason. Obviously everyone is different and many of the penalty takers have a certain side, they go there, they choose the side before, they go powerful and they still score.
“I don't know. It was something I learned from Fabio Quagliarella at the time I was at Sampdoria. He was always checking with the goalkeepers in terms of what he should do, about the way he kicked and everything.
“He had a quick run-up and a very powerful shot, but he was always trying to understand the movements of the goalkeeper and I got that from him. I always want to learn from the best ones.”
Fernandes says he taps Portugal teammate Cristiano Ronaldo for tips on penalty taking.
“When we go away with the national team, I'm always having chats with Cristiano, to understand the way he does it, and we do speak a lot.
“He sometimes asks me what I think about the goalkeeper and everything. Even Cristiano, if you see now compared to the past – if I see Cristiano's penalty against Chelsea in the final of the Champions League, and the ones he has taken after that, he's changed his way of kicking.
“Now he's changing again, so you always have to adapt yourself to the game, because things change quickly, people get to know you better and better, so sometimes you need to do something different.
“If you ask anyone in the world who you would choose to take your penalty, after 90 minutes, to save your life or whatever, most people will say Cristiano, because they know in that kind of moment he's decisive and it works.
“If Cristiano is one of the best penalty takers in the world and he's changing, why shouldn't I do the same? Why shouldn't I improve myself and try to do different things?”