The 26-year-old winger brought his season's tally to 12, adding two second-half tries to his seventh-minute opener.
Lam's first try gave the Hurricanes an up-tempo start to the game in blustery, swirling conditions at Westpac Stadium on Saturday.
Both teams were guilty of coughing up possession too easily, but it was the Hurricanes who made the most of their chances.
The late loss of Jordie Barrett to an ankle injury didn't affect their running game, with Nehe Milner-Skudder slotting in at fullback in his second game after returning from shoulder surgery.