That took his tally of goal contributions to 17 for the season, with stats showing United would be on just 22 points without his goals or assists.
Rasmus Hojlund and Alejandro Garnacho ended 21-game and 25-game goal droughts respectively at the King Power but boss Amorim reserved special praise for his captain.
He said: “Bruno is a special guy. I always see a Bruno who is dangerous.
“What surprised me the most is the way he works every day. He’s a very good professional.”
Fernandes is delighted to have done his bit for the club again.
He said: “I want to score as many goals as I can. It's a big part of my game.”
The only blot for United was a serious injury to defender Ayden Heaven.
The 18-year-old made a series of vital clearances and challenges in the first half, none more so than a double block just before the break as the summer recruit from Arsenal underlined his huge potential on only his second United start.
But Heaven's night ended just a few minutes after the restart when he was forced off after falling awkwardly defending a cross from Jamie Vardy.
It was a cruel end for Heaven, who exited on a stretcher and later left the stadium wearing a protective boot on his right foot. Leicester were the perfect cannon fodder for Amorim's charges.
They have faced the Foxes four times this season - twice in the league and in the FA plus Carabao cups - and won them all.
Hojlund had gone 22 hours and 19 minutes without a goal but showed supreme composure t...