The better team was beaten this afternoon, with Forest dominating for 90 minutes before a cruel stoppage time goal gave the home side the win.
Forest's performance was much improved from Tuesday night's although chances were few and far between in the first half, but it was the Brighton keeper who was by far the busiest, with Lee Camp hardly tested.
It was a much more lively second half with Forest dominating and producing some great chances but Brighton, who hadn't produced a single shot on target, got a last minute winner to take all the points.
Forest started well and good play involving several players got the ball forward for Garath McCleary
who, making his first appearance following injury, won Forest a corner. It was taken by Jonathan Greening
who played the ball short, got it back and put in a cross which was only just over the head of Wes Morgan
at the back post.
A good pass by Guy Moussi
created a chance for Paul Anderson
who made a run forward before shooting but, with Ankergren diving to make the save, the ball flew just wide of the far post.
Brighton also had their chances early on and made a good more forward, with Craig Noone doing well to get into the box and put in a low cross where Moussi did well to get back into the penalty area and put the ball out for a corner.Good passing and movement from Forest which ended in Radi Majewski's left wing cross going just too high for Tudgay in the middle.
And Forest threatened just before the break with a great run by Majewski who got past Alan Navarro on the edge of the box before being brought down by the Brighton player, winning Forest a free kick 20 yards out just left of centre, but it came to nothing.
Forest came close to taking the lead early in the second half starting with some great skill by Majewski who combined well with McCleary to get forward. The ball was fed through to Chris Gunter
whose cross came in for Marcus Tudgay and his diving header was only just wide of the near post.
And they continued to push forward with McCleary getting on the end of Greg Cunningham
's cross and making his way past the Brighton defence and into the box, but he couldn't quite divert the ball goalwards.
Again they got behind the Brighton defence and Anderson's cross was deflected right across the six-yard box and trickled just wide of the post.
Brighton had their best chance of the game so far with a cross from substitute Kazenga LuaLua to the back post but the header from Noone went just wide.
McClearey produced some great work on the edge of the box to get away from two but his shot was deflected off Lewis Dunk and the ball looped up in the air and onto the top of the net and out for a corner.
And from Jonathan Greening
's corner Tudgay did well to get on the end of the ball but sent it straight into the arms of Ankergren.
More great work from Majewski came close to him hitting the target after he ran away from the challenge of Noone and curled the ball through the six-yard box and fizzes just wide of the far post.
McCleary's return produced an excellent 81 minutes of football although he was looking a little tired when he was replaced by David McGoldrick
And with Forest looking to protect their point, Brendan Moloney followed him in the 89th minute in place of Anderson.
But in the final minute of stoppage time Brighton got the winner when Craig Mackail-Smith got away down the right and laid the ball into the box where substitute Romain Vincelot laid the ball back to substitute Will Buckley who slotted it past Camp.Forest:
Camp, Chambers(C), Morgan, Gunter, Cunningham, Moussi, Greening, Majewski, Anderson(Moloney 89min), McCleary(McGoldrick 81min), Tudgay
Subs not used: Smith(GK), McGugan, Blackstock.
Bookings: Tudgay 66minBrighton:
Ankergren, Greer(C), Dunk, Navarro(Vincelot 85min) Barnes(LuaLua 55min), Noone(Buckley75min), Mackail-Smith, Paynter, Bridcutt, Taricco, Jara.
Subs not used: Brezovan(GK), El-Abd,
Bookings: Dunk 89min
Scorer: Buckley 90+2min
Referee: Darren Drysdale
Attendance: 20,385 Away attn: 2,402