Auckland have now put themselves in a royal and rare position to garner the maximum 15 points from a short turnaround three matches in eight days.
The first spell saw Auckland stretch the Turbos' defence to breaking point. They scarcely made an error for the first half hour, and could have had the bonus point by oranges if the Turbos had not scrambled well and Karpik had not offended the rugby gods.
Twice the blond flanker, looking like some modern day Jean-Pierre Rives hurtling about Eden Park, was over the line, but had his foot on the touchline the first occasion and then ran into prop Jono Owen's backside for the second.
All three Auckland first spell tries actually stemmed from lineouts. Moala scored the first, stripping his teammate, hooker Kurt Eklund, of the ball and diving over. The pinball second five was, however, subbed at halftime.
Lam again showed his power with his fourth of the season, before adding a second. Owen scored the third off a lineout steal.
But the Turbos' resistance was far from over, captain Callum Gibbins diving over from yet another lineout drive.
They rattled on three second spell tries to secure a bonus point and showed far more mettle than their listless opening. One of those tries, to fullback Semisi Masirewa, saw him pull out a prodigious fend.
Auckland line up again at Eden Park on Sunday in the Lin Colling Memorial Trophy and crossover clash with Otago, while Manawatu host Northland in a crossover later that afternoon.
Auckland 45 (Ben Lam 2, George Moala, Jono Owen, Rieko Ioane tries; Simon Hickey 3 con, 3 pen, Jono Hickey pen, Mitch Hunt con) Manawatu 28 (Callum Gibbins, Valentino Mapapalangi, Semisi Masirewa, Fraser Stone tries; Otere Black 4 con) Halftime: 30-7