Forest came into this game on the back of successive victories, and Nuno Espirito Santo’s side started the match on the front foot.
In turn, they went close to taking the lead inside 16 minutes after the ball fell to Taiwo Awoniyi inside the penalty area, but his strike across goal was kept out by a smart save from Bart Verbruggen.
However, that start began to wane as the half went on, with neither side really managing to control the game.
The Seagulls finally had their first shot on target after 31 minutes, when Pervis Estupinan’s strike from distance nearly caught out Matz Sels after the ball bounced just in front of the Belgian, but the keeper managed to push the ball to safety.
Brighton continued to grow into the game from there, and went close again on the brink of HT after the ball fell to Carlos Baleba on the edge of the area, but his left-footed volley went inches wide of the right post.
Forest went close again three minutes after the restart, this time from Morgan Gibbs-White’s strike from the edge of the box, but Verbruggen was able to tip the ball just over the crossbar.
Unsurprisingly for this back-and-forth affair, the next-best chance came for the hosts, when Jack Hinshelwood rose highest from a corner, but the defender couldn’t get his header on target and the ball went out for a goal kick.
However, after 90 minutes there was nothing to separate the sides and the game went to ET.
Brighton went agonisingly close to taking the lead early in the second half of ET, when Diego Gómez headed Brajan Gruda’s cross goalwards, only to be denied by a stunning save from Sels.
The Seagulls thought they’d won it with just two minutes to go when Joao Pedro squared it to Gómez who poked it home, but it was ruled out for offside.
The match ended goalless and had to be settled by a penalty shootout and ultimately it came down to Ryan Yates to capitalise on Sels two penalty saves, and he rifled the ball into the bottom-left corner to win the shootout for Forest and send them to their first major semi-final in 34 years, via their third FA Cup shooutout success this season.
Flashscore Man of the Match: Pervis Estupinan (Brighton)