Millwall suffered an FA Cup hangover as they failed to score at home for the first time this year.
The Lions' Cup success had taken its toll on the side with player-boss Dennis Wise, captain Kevin Muscat and winger Paul Ifill all missing through injury.
And the players who made it onto the pitch looked as if their minds were on the final in Cardiff rather than their Welsh opponents, who had their own play-off hopes to consider.
Despite the drab performance, Millwall move up to fifth with this point - but boss Wise will be getting concerned at the end of season fixture pile-up.
Cardiff forward Robert Earnshaw was the most dangerous of the visiting team and should have put his side in front on 26 minutes but sliced wide when faced with an open goal.
And apart from a couple of Danny Dichio half chances Millwall fans had little to shout about on their side's homecoming from Old Trafford.
It took the half-time introduction of teenager Marvin Elliott for Millwall to show any bite and he came within a whisker of scoring on 54 minutes when he forced keeper Martyn Margetson into a diving save.
He then provided Neil Harris on the hour only for the striker to blaze over the bar when he was under no pressure.
Eight minutes later 19-year-old Elliott let fly with a 25-yard bullet which curled just wide of the post, before Dichio's effort took a deflection off a Cardiff defender to go out for a corner.
Cardiff's visiting fans were surrounded by a strong police presence, and the match itself was played in poor spirit with a total of eight players booked by referee Mick Fletcher, before last Sunday's goalscorer Tim Cahill was sent of in injury time for a second yellow card.
Gary Croft was lucky to stay on the pitch for the visitors when he appeared to stiff-arm David Livermore just two minutes after being booked.