Nottingham Forest's second away win of the season saw them finish the day in sixth position on goal difference. It was a magnificent team effort from a well-organised, hard working Forest side that thoroughly deserved all three points.
A strong, disciplined first half performance and another great goal by Lewis McGugan saw Forest go in at half time in the lead over Championship leaders Cardiff.
Forest dominated much of the second half and were rewarded with a second goal by Dexter Blackstock. But the afternoon finished in tragedy for the Forest striker who was stretchered off injured just before full time.
It was just two minutes before Forest made a good move forward with a good pass by Lewis McGugan to Ryan Bertrand whose shot across the six yard box came very close to making contact with Robert Earnshaw.
But Cardiff looked threatening from the outset, with two shots from Craig Bellamy missing the target in the opening four minutes and they came close from a free kick when Peter Whittingham's effort curled just over the crossbar.
And the home side missed a good chance when Bellamy put a good ball through to Jay Bothroyd, who beat the offside trap and got round Lee Camp only to shoot into the side netting.
But it was Forest who took the lead, in the 24th minute, with another great goal from McGugan. Dele Adebola won the ball in the air and gave it to McGugan who curled the ball into the top corner from 22 yards out.
A great move by Guy Moussi got him clear of Whittingham and he got as far as the box before being closed down to win a corner for Forest.
Great movement forward by Forest and a great finish by Robert Earnshaw saw the Cardiff keeper scrambling for the ball but the offside flag went up.
Forest kept their composure and looked confident and the first half finished without Camp having a single save to make.
Cardiff came close to an equalizer early in the second half after a good run by Bellamy and a cross to Bothroyd. His header from point blank range was headed straight for goal but Camp was in the right place to deny the Cardiff striker his 16th goal of the season.
But Forest continued to hold their own and another long-range effort from McGugan only just missed Luke Chambers at the far post.
Earnshaw received warm applause from all four sides of the ground when he was replaced by Dexter Blackstock with 20 minutes remaining.
There was another chance for Cardiff when the Forest midfield let Bothroyd through on goal but he couldn't get away from Bertrand and the ball was put out for a corner.
Good work by Adebola won him the ball to give him a shot on goal. He tried to place it low into the right corner and&nbsp;Tom Heaton&nbsp;took two attempts to gather up the ball.
McGugan turned provider for Forest's second goal with a great run down the wing before turning his man. He looked up and put in a perfect ball for Blackstock who rolled it low into the corner.
Forest created another chance with a great ball from Adebola to Blackstock on the edge of the box, but Whittingham's challenge prevented the ball from falling for Moussi.
It looked like a serious injury to Blackstock when he turned badly and went down, putting his arm quickly in the air to call for help. Paramedics were called for quickly and that was followed by a doctor and Blackstock was stretchered off with his leg in a splint.
As the game went into six minutes of stoppage time Cardiff missed a chance to get one back after a long ball forward was crossed to Bothroyd who headed to Bellamy as he ran into the penalty area, but he shot over the crossbar.
And as Cardiff continued to push forward, Camp had to put another attempt by Bellamy out for a corner.
But it was all to late for the home side who suffered a rare home defeat.
Nottingham Forest: Camp(C), Gunter, Morgan, Chambers, Bertrand, McCleary(Lynch 84min), Moussi, Cohen, McGugan, Adebola, Earnshaw(Blackstock
Subs not used: Smith(GK), Majewski, Thornhill,
Bookings: Chambers 64min, McCleary 71min, Cohen 81min
Scorer: McGugan 23min, Blackstock 84min
Cardiff City: Heaton, McNaughton, Hudson, Gyepes, Whittingham, Koumas, Olofinjani, Blake(Matthews 81min), Bellamy(C), Chopra(Drinkwater45min HT), Bothroyd
Subs not used: Marshall, Rae, Wildig, Keogh
Referee: C H Webster