The dual international centre chalked up his first treble since 2005 with three tries in 12 minutes, either side of half-time, as Wayne Bennett's side produced their most impressive performance in a disappointing season in front of a crowd of 18,637.
The visitors started in fine fashion, opening up a 14-0 lead after 22 minutes, with skipper Robbie Farah impressing in his first game back since the death of his mother last Sunday.
The NSW hooker set up Chris Lawrence after 10 minutes with Lote Tuqiri adding another four points when he latched onto a Benji Marshall kick, before the Kiwi playmaker kicked his third goal of the half with a penalty.
However, the hosts fought back well with axed NSW winger Akuila Uate scoring in the right corner on the half-hour mark, before Tahu ran in two quickfire tries just before the interval.
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.