Goalkeeper David Marshall could only watch on in disbelief as Cardiff City imploded against his former employers.

The former Celtic stopper left Norwich City in 2009 and has gone on to become a hero in Wales thanks to a string of outstanding displays. But he was powerless to prevent the Canaries from storming to a 4-2 win on Saturday as the Bluebirds blew a two-goal half-time advantage to taste a disastrous defeat on their own turf.

Marshall said: 'We played really first half and we knew how big a game it was going to be because I think Norwich will be there or thereabouts at the end of the season as well.

'The second half was very poor. In the first half-hour we let the game slip because at half-time we were looking good. We spoke about starting the game well as we've not really done that this season so far. In the first half we were great. We created a few chances and went 2-0 up. But our concentration for the first 10, 15 minutes of the second half has let us down.

'It's disappointing for everybody. Even at half-time we spoke about concentration and keeping it going. For things to turn that badly of course he (boss Ole Gunnar Solkskjaer) was angry, everyone was.'

Marshall was beaten from close range by Martin Olsson, Wes Hoolahan – after the Scot had initially denied Cameron Jerome – and Michael Turner before being rounded by Jerome late on to heap more misery on the Welsh giants. And the Cardiff number one admits it could have been so different had Federico Macheda made it 3-0 early in the second half.

'It's fine margins. It was a half-chance for Kiko (Macheda) and it was a good save from John (Ruddy),' added the goalie, who thought at least one of Lewis Grabban and Turner were offside when the Canaries made it three.

'The defending was not what we expected. As a team we were very poor for 20 to 25 minutes. To concede three goals at home is bad enough in a game but especially for 2-0 up, we shouldn't be conceding goals like we did. It's a bad defeat against one of our rivals that we think will be up there. We just have to keep winning games now if we can and start putting a run together.'