The match was an uninspiring bout which looked to be going to extra time after both sides had the ball in the back of the net in the second half, all for the goals to be ruled out for offside.
However, somehow with practically the last kick of the game, Iheanacho was unmarked in the Seagulls box and headed past Chris Walton in the net, thanks to a glorious cross from Youri Tielemans.
Cup specialist Iheanacho
The Super Eagles forward scored for the second time in a week which will certainly do him the world of good. For a centre forward that doesn't get too many chances it's a great confidence booster to score when given the chance.
The former Manchester City striker scored his 11th FA Cup goal of his career in only 17 appearances, the perfect back up man to rely on in the cup.
Daley-Campbell shines on debut
Vontae Daley-Campbell played a full 90 minutes on his Leicester senior debut, and the youngster definitely impressed.
Having signed from the Arsenal academy as an 18-year-old, just over 18 months later sheer hard work and growing as a footballer has led to Rodgers selecting the defender for his first team debut.
However, being thrown into the deep end last night in the fifth round of the FA Cup, the teenager showed he was more than up for the task.
He did not put a foot wrong and proved to be an attacking threat in a more advanced wing back role to what he would usually be used to playing in the u23's.
Vardy and Ndidi get an hour
Jamie Vardy and Wilfred Ndidi both played 60 minutes in their road to full fitness after both missing the last few games with injuries, in which they both recovered exceptionally well from.
It was a quiet night for both but it was a real relief for Foxes fans to have two of their most important players back on the field, as Leicester's injury list in the last year has constantly had new additions.
There was certainly some concern when arguably the home side's player of the season James Justin went down with an injury to his knee. The versatile full-back has played a pivotal role in Leicester's success this season playing on both sides and running up and down the touchline all game long.
Rodgers and his medical staff are hopeful the injury won't be nothing more than just a sore knee as he jolted it.
The East Midlands outfit have made it to the quarters of the FA Cup for the first time in over 50 years.