The victory, against Pearson's former club, maintained the Foxes 100% home record and lifted them to seventh in the table.
Pearson said: "It was good for Nugent to get the hat-trick and he proved you have just got to keep working hard when things are not going your way. Strikers thrive on confidence and we got the result we deserved."
Nugent, who scored the 100th League goal of his career against Burnley on Wednesday night, struck the Foxes' opener in the seventh minute after Danny Drinkwater's shot had landed at his feet. But against the run of play, Hull equalised in the 25th minute when Sone Aluko set up Jay Simpson for a simple goal.
Nugent headed Leicester in front again from a Anthony Knockaert cross just before half-time and completed his treble with a clinical finish in stoppage time.
Foxes boss Pearson added: "I think it was a deserved win. We were the better side all through the game and dominated the second half in terms of territorial advantage.
"Four home wins in a row is obviously very pleasing but clearly we need to get our away form going. But when you look at it in it's entirety it is 12 points from seven games in a very tough start to the season, and we could easily be three or four points better off."
Hull manager Steve Bruce was ordered to the stands after an 83rd-minute confrontation with an assistant referee over a throw-in. Bruce apologised to the assistant referee after the match and admitted he had acted stupidly, but had no complaints about the defeat.
He said: " We did not deserve anything. We have to say Leicester were worthy winners. The better team won on the day and we are very disappointed after the way we have played over the last few weeks. But we were nowhere near their level today.
"I have just been into see the referee to apologise. Sometimes you do some stupid things, at my age especially. I contested a decision that had gone against us but I still shouldn't go on like some raving lunatic, which I did and I have apologised."
Source: PA
Source: PA