Below, Sports Mole picks the bones out of an incident-filled game in the Welsh capital.
On target 8
On target 6
Was the result fair?
Oh yes. Cardiff had looked the more dangerous before Helguson was left unmarked to head in Craig Bellamy's free kick and from then on it was plain sailing for the league leaders. Henderson's dismissal of course helped massively and they could have had so many more goals in the second half.
A solid enough start by the hosts and they were presented with the easiest of chances to go ahead when no-one bothered to track Helguson's run. The red card before half time was a massive boost and Mackay's men didn't let up in the second as substitute Gestede powerfully headed home twice while his teammate spurned chance after chance.
Billy Davies has galvanised this side into a late push for the playoffs but their streak under his management had to come to an end sooner or later and there's no real shame in losing it at the league's pacesetters. They were holding their own until Henderson's dismissal but didn't cope well at all with having a man less and were lucky to concede just two further goals.
Sports Mole's man of the match
Kim Bo-Kyung: No goals for the midfielder but Kim was at the heart of all things good Cardiff produced. He was very composed when on the ball and distributed it sensibly throughout.
Cardiff's two Craigs, Noone and Bellamy, can fight it out for this award after they both missed open goals from tight angles at the back post towards the end.
Andre Marriner was a little card-happy today and made a questionable decision in sending off Henderson. Yes, the forward's arm did catch Helguson in the face but his eyes were fully on the ball and it didn't look intentional. Marriner may have been influenced by the fact that just moments earlier there was a little skirmish in the area and maybe he felt it was related to that.
Cardiff: Next up for Cardiff is a visit from Charlton on Tuesday where a point will be enough to guarantee top-flight football for the first time in 51 years.
Forest: Davies's men, meanwhile, go to Middlesbrough in three days' time.