The Foxes frontman scored twice inside six second-half minutes after the home side had taken a lead with little over 100 seconds on the clock.
David McGoldrick caught Kasper Schmeichel cold from 25 yards as Ipswich threatened to shock a Leicester side looking to leapfrog leaders Burnley.
But Nugent has become an arch-nemesis of the Suffolk side and his quick-fire double saw Leicester move level with Burnley and third-place QPR.
It also increased his individual tally against Ipswich to an incredible 13 goals in 12 games - and nine goals in seven games at Portman Road.
Pearson was left perplexed by the prolific run, preferring to praise Nugent for his reaction to missing some gilt-edged chances in the defeat to Nottingham Forest last time around.
The Leicester boss said: "There is no reason for it, but I am pleased it has carried on today.
"Like any striker, there are going to be spells when goals are a little scarce. He has to keep getting in the right areas and he scored two good goals.
"He also needs a manager to back him, which he has."
Pearson, who made two changes at the interval, was pleased with his side's comeback after the early setback - while Ipswich had little answer to Nugent's double.
The Foxes restored parity in the 51st minute when Lloyd Dyer flew down the left and his cross was teed up by Jamie Vardy into the path of Nugent who made no mistake.
Five minutes later, Leicester took the lead when Dyer broke clear to round Gerken and feed Nugent to score the winner from close range.
Pearson said: "It is always good to have a bit of pace and that made us dangerous in on the counter attack.
"David Nugent will get all the headlines but Lloyd Dyer and Danny Drinkwater did exceptionally well. The most important thing is that we got all three points."
Having been pleased with his side's first-half performance, Town boss Mick McCarthy pointed to errors made in the build-up to both of Nugent's goals.
He said: "There are not many players in this league who would have struck that equaliser like David Nugent did.
"But the goal came after we closed down their keeper and the ball ended up in our net. And for the second goal, we were attacking them and it ended up in our net.
"We made error after error and we were punished. That's the difference in this league when you play one of the best."