The division's league leaders managed to end Forest's streak by comfortably seeing off the 10-man visitors 3-0 to all-but secure promotion to the top flight.
Read how it all unfolded in the Welsh capital in our minute-by-minute live updates below.
2.01pmAfternoon folks! This is a massive match for both sides as Cardiff look to strengthen their position at the Championship's summit while Forest could further cement their place in the playoffs.
2.03pmTeam news should be available shortly and the players will be doing battle in front of a sell-out crowd at the Cardiff City Stadium. Great news.
2.06pmRAIN! Weather-wise in the Welsh capital it's a very damp day, with temperatures hovering into double figures at 10-11 degrees celsius.
2.08pmFOREST XI: Darlow, Jara, Ward, Halford, Cohen, Guedioura, Lansbury, McGugan, Majewski, Henderson, Blackstock
2.09pmCARDIFF XI: Marshall, McNaughton, Barnett, Turner, Taylor, Gunnarsson, Mutch, Kim, Smith, Bellamy, Helguson
2.10pmMackay is unable to select either Frazier Campbell or Matthew Connolly, who have shin and groin problems respectively.
2.12pmSUBS: Here are the two benches:
Cardiff: Lewis, Nugent, Whittingham, Gestede, Noone, Conway, Mason
Forest: Evtimov, Harding Collins, Moussi, Reid, Tudgay, Sharp
Cardiff: Lewis, Nugent, Whittingham, Gestede, Noone, Conway, Mason
Forest: Evtimov, Harding Collins, Moussi, Reid, Tudgay, Sharp
2.15pmIt's always surprising to see Peter Whittingham on the bench for Cardiff. He has been an ever-present in their side in the last few seasons but has struggled to secure a first-XI place every week this year.
2.18pmThe home side have a veteran front duo but age is no issue when Heidar Helguson and Craig Bellamy link up so well.
2.22pmFor the visitors it's a midfielder who is perhaps their most dangerous player. Lewis McGugan is on fire at the moment. He can't stop scoring and has been one of the keys to Forest's 10-game unbeaten run.
2.25pmDespite that impressive stat, Forest have drawn three on the bounce and have stuttered a little in their push towards the top.
2.28pmELSEWHERE! There was one early kickoff in the Championship and it's just finished at Elland Road where Brian McDermott has picked up a win in his first game in charge against Yorkshire rivals Sheffield Wednesday. The Owls were ahead at the break thanks to Jermaine Johnson's fourth in four but came out on the losing end because of a second-half brace from Luke Varney. Read our report here.
2.33pmUnder half an hour until we begin in South Wales. As mentioned, a win for Cardiff will all but secure Premier League football. As it stands, they're six points clear of Hull but if results go their way today then they will only require a point or two from the final four games.
2.37pmCardiff's last four games are against Charlton (H), Burnley (A), Bolton (H) & Hull (A). If they do go on a bad run then that match at Hull on the final day will be huge!
2.40pmHull travel to Ipswich Town this afternoon and although they may be fancied, Ipswich haven't conceded a goal for five games and are playing much much tighter under Mick McCarthy.
2.44pmCardiff's only other possible challengers for a top-two finish, Watford, go to another struggling side, Peterborough, this afternoon. I'll keep you up to date with all the big goals as they go in, fear not.
2.47pmREFEREE WATCH: Today's man in charge is Andre Marriner, who usually officiates in the Premier League.
2.50pmPREDICTION TIME! With 10 minutes until the off, it's time for my prediction on the match. Cardiff are stumbling slightly and I'd be surprised if they end Forest's unbeaten run today. They should have enough defensively to stifle the visitors so I'm plumping for a draw.
2.54pmThere's plenty of other action on SM today and you can find our other football live commentaries here.
2.57pmKickoff just moments away now and it's a raucous atmosphere inside the Cardiff City Stadium. Will Malky Mackay's side move even closer to Premier League football? Here come the teams out of the tunnel.
3pmCardiff are in their new colours of red tops, black shorts and red socks while Forest are in their changed strip of aqua blue tops, white shorts and blue socks.
0 minKICKOFF! Referee Marriner blows his whistle for the first time and Forest get the game underway.
2 minLittle to report in the opening couple of minutes as neither side manages a decent string of passes together. Early goals in the Championship as rockbottom Bristol City concede early to Bolton while Wolves have gone ahead against Huddersfield in a big game at the bottom.
6 minBellamy with his first impact on the game as he gets to the byline and looks for a red shirt with the cutback but it's well defended and cleared by Forest.
7 minSmith beats the offside trap down the right touchline and then tries to pick out big man Helguson at the back post with a floated cross but Darlow does well to rise up and pluck it out of the air.
11 minWell we know Bellamy has plenty of class but he's not going to score by doing that as he decides to shoot from about 40 yards with plenty of space to run into.
12 minSHOT! First decent effort of the match comes from Forest as Cohen lays the ball back for Guedioura to fire goalwards from 25 yards. He cut across it and got plenty of swerve on it but it didn't quite bend inside the near post. Cardiff are unhappy that Forest didn't put the ball out of play as Mutch was down injured.
14 minCardiff respond well as a messy free kick eventually breaks to Helguson and he attempts a volley from just inside the area that doesn't quite dip enough to get under Darlow's crossbar.
17 minNot so good from Bellamy this time. Left-back Taylor makes a great run past a couple of blue shirts before feeding inside to Mutch who drives at the area before the ball falls for Bellamy on the left of the area. He feints inside onto his right but spoons his curler way over the bar.
22 minGuedioura certainly isn't afraid to shoot but his latest effort doesn't even make it close because of Turner's brave block.
23 minYet again it's Guedioura who lets fly from distance after twisting and turning on the edge of the area. His shot does make it through the crowd this time but Marshall holds on despite an awkward bounce just in front of him.
25 minYELLOW! First booking of the match goes to Forest's Halford for a body check on Kim. Free kick to Cardiff in a dangerous position left of centre. 35 yards or so out...
26 minGOAL! Cardiff 1-0 Forest (Helguson)
26 minEver so easy for Cardiff as Bellamy curls it in perfectly to the back post where an unmarked Helguson can't miss with a header from just a couple of yards.
3.30pmUPDATE: There's been a goal in both games involving Cardiff's promotion rivals. Hull have just gone one ahead at Ipswich with a penalty but Watford are losing at Peterborough.
32 minMcGugan is furious as he's called for a foul before turning away and curling a peach of an effort into the far corner. It was a fairly soft decision as the Forest man just seemed to outmuscle Turner.
35 minCHANCE! Oh what a chance for Forest to equalise! Lansbury is slipped in and his original shot is parried straight back to him by Marshall. He then sends a diving header back across goal and all it makes its way to Henderson at the back post and all he has to do is stroke home but he doesn't connect well and Marshall is able to scramble back and jump on the ball.
36 minYELLOW! Another booking for Forest and this time it's Jara who is cautioned by Marriner.
39 minSAVE! Cohen is tripped by McNaughton on the left and from the resulting free kick McGugan surprisingly seems to go for goal and a back-peddling Marshall just about tips it over.
43 minRED CARD! Forest's Darius Henderson is off!
43 minApologies, it originally looked Halford was the man to be dismissed, but it's striker Henderson. Replays show that his arm/elbow did catch Helguson as a Forest free kick was pumped into the area. However, his eyes were only on the ball and that's ever so harsh.
45 minCardiff are all over this match now as Smith sneaks to the byline before looking for Helguson with a deep cross. Good defending from Jara though as he heads out for a corner.
45+1 minYELLOW! Another man in the book and this time it's Cardiff's Mutch for a deliberate handball in the area. Four minutes have been added on, by the way.
45+5 minHALF-TIME: Cardiff 1-0 Forest
3.51pmAn incident-packed half of football in the Welsh capital then. Cardiff are both a goal and a man up and surely this is theirs to lose now?
3.56pmTo see the table as it stands, click here. As you can see, Cardiff are set to open up an almost unassailable 12-point lead back to Watford in third. There's only four games left after today so Malky Mackay's side would have to lose all four while Watford would have to win all four!
3.59pmIf you've only just joined us and want a summary of the opening half then you can find our HT report here.
4.01pmThe second half will be underway shortly but we're a little delayed because of the five minutes added on at the end of the first.
4.03pmWhat will Billy Davies have told his players during the interval? They face a mighty task if they are to preserve their 10-game unbeaten run with a man and a goal less than their opponents. Will he make a change or two early on?
4.08pmFinally we're going to begin the second half but not before Forest do make a change and unsurprisingly it's a striker in Marcus Tudgay. He replaces Majewski while Cardiff have also made a sub with Rudy Gestede on for goalscorer Helguson. Interesting.
47 minWe were late starting the second half and there's already a hefty delay in play as Halford stays down after taking a knee to the face. Looks like the stretcher might be needed.
50 minFOREST SUB: Unfortunately the Forest man does have to leave the game. He's replaced by Danny Collins.
4.17pmPlenty of goals going in in the Premier League, see the right of this page for the latest scores.
4.18pmUPDATE: Great news for Cardiff as Hull are pegged back by Ipswich. Anthony Wordsworth with the equaliser for his first Tractor Boys goal.
57 minForest seem happy to push men forward and expose themselves on the counter. I'd be amazed if this one finishes as it is now.
59 minYELLOW! Blackstock and Guedioura are cautioned for a pair of nasty tackles.
59 minGOAL! Cardiff 2-0 Forest (Gestede)
59 minDidn't I say a goal looked on the cards? Cardiff's second comes after Bellamy's free kick struck the post and bobbled out to the left. The hosts eventually managed to cross it back in again and there was substitute Gestede to head home.
4.26pmUPDATE: It gets better for Cardiff as Watford go 2-0 down at Peterborough. This is promotion to the top flight for Malky Mackay's side today. Not mathematically, but it is.
64 minGoodness me, this could turn into a rout. Forest are completely lost at the moment as Cardiff pepper Darlow's goal. Somehow it remains 2-0 after Barnett squanders the latest chance by heading wide.
65 minSmith is the next to have a go as Kim sets the ball back for him to strike from 20 yards. It's well hit but Collins slides in to deflect it out for a corner.
66 minGOAL! Cardiff 3-0 Forest (Gestede)
66 minIt's just so so easy for the hosts at the moment. It's Gestede again who gets up above the Forest defence to head home Bellamy's corner.
4.30pmUPDATE: It's goals galore at the moment in the Championship. Huddersfield have turned it around against Wolves and lead 3-1 while Peterborough are now three up on Watford.
4.33pmIt had to come to an end somewhere, and I guess it's not the worst scenario that Forest have lost their unbeaten run at the league leaders. Hardly ideal ahead of the final playoff push though.
71 minSHOT! Tricky feet from Kim on the edge of the area before he looks for the near corner but can't generate enough bend on his shot. Can Forest keep it to just three?
74 minAs it stands, Forest will drop to sixth place and lie just two points ahead of Leicester in the final playoff place.
74 minCARDIFF SUB: Second change of the match for Mackay and it's Craig Noone who comes on for Tommy Smith.
77 minWHAT A MISS! It should be four but Bellamy has just sent in his contender for miss of the season as he manages to hit Noone's cross into the side-netting with no keeper in front of him.
4.45pmUPDATE: Hull retake the lead at Ipswich as Robert Koren heads in. Looks like Cardiff and Hull are pulling away at the top.
85 minYELLOW! Another booking for Forest and this time it's substitute Moussi who picks up a card for diving in late.
87 minThis is Cardiff simply coasting to promotion now. There may be four games left of the season but today is the day they've sealed it. Congratulations to them.
88 minCARDIFF SUB: Third and final change from Mackay and it's Whittingham on for Mutch.
90 minFull times up and down the country. See the box on the right for the latest scores. In Cardiff, four minutes are added on.
90+1 minMISS! Another shocking miss at the back post from Cardiff. This time it's Noone who can't get his angles right and hits the side-netting like Bellamy a little earlier.
90+4 minFULL-TIME: Cardiff 3-0 Forest
4.57pmThey won't have a P next to their name but Cardiff City are as good as promoted to the Premier League.
5pmClick here to see the latest Championship table. Cardiff are now 12 points clear of Watford in third with just four games to go. Therefore, Mackay's side will need to lose all of those games and Watford will have to win all four. Not going to happen.
5.04pmThanks for joining Sports Mole for an action-packed game of football in the Welsh capital. Click here to read our match report if you want a shorter summary of the match. Yet again, let's congratulate Cardiff on their soon-to-be-confirmed promotion to the Premier League. They'll be playing top-flight football for the first time since 1962!