Queensland and Australia star Darius Boyd had a hand in all three of the tries, and was the architect of Tahu's third just after the restart with a neat pass to give the home side a comfortable advantage.
With their confidence now soaring the Knights dominated the second period and extended their lead on the hour when back-rower Chris Houston rolled over for his third try of the year.
Tim Sheens' side's misery was compounded 16 minutes from time when Beau Ryan was sin-binned for preventing Jarrod Mullen from making a quick play-the-ball and Tyrone Roberts converted the penalty.
Roberts added his seventh goal of the night with another penalty after Marshall was adjudged to be offside from the kick-off, before James McManus scored a sixth try for the hosts late in the game.
The disappointing Tigers had the final say with a try on the siren from Masada Iosefa, with Marshall adding the extras.
Bennett said the manner of his side's performance did not surprise him, but urged his players to be more consistent.
"Confidence is a bit hard to be define and what it gives to you and where it goes, but I would suggest we need to start doing it two or three weeks in a row and have some real belief,'' Bennett said.
"They can do some special things these guys, but just need to do it on a consistent basis.''
Tigers coach Tim Sheens cut a terse figure after the game and said the disruption caused by the emotion around the club this week was not an excuse for the poor display following a bright start.
"I am not in a mood to assess who did well, I am not in a happy mood at all,'' Sheens said.
"I have a good look at the video this week and go from there.''
Sheens also confirmed fullback Tim Moltzen would be out for up to three weeks with a hamstring problem.''
Skipper Farah, who grieved at his mother's funeral last Wednesday, declined to talk to the media after the game.
- AAP
